Here a link to three pictures of the rhododendron in question. One from a year ago and two recent ones (One close-up)

Here is a link that might be useful: Deformed leaves

What side of the plant is that? South? Or west?

I ask because those leaves show damage from the sun, ranging from yellowing (killed chlorophyll) to burn (the dead spot).

May be a simple as the plant hasn't yet rooted into the surrounding soil. Thus, the rootball is running short of water.

So, poke around under the shrub and feel the soil in that area. If needed, slowly drip the hose directly onto the rootball as needed.

The deformed leaves are on the western side of the plant. Last summer was one of the hottest in history and many of my rhododendrons showed some sun-burn damage on the south-western side, but only this one had its leaves become so small and deformed as well. I will correct the problem with sun exposure this summer, but I thought there might be more to it than just sun burn.

There are several possibilities.

One possibility is Exobasidium Leaf and Flower Gall, Exobasidium vaccinii which is a very common fungal disease in the spring during wet, humid, cooler weather on azaleas and occasionally on rhododendrons. In April and May leaves and buds of infected plants develop distorted growth.

Another is Long-tailed Mealybug, Pseudococcus longispinus which creates small cottony masses with long, waxy filaments extending from one end is a symptom of the long-tailed mealybug, Pseudococcus longispinus, which is a sucking insect that colonizes on the least accessible parts of plants. Since it is hard to see, systemic insecticides are preferred, but thorough treatment with a contact insecticide may provide control. Infested plants will have honeydew and sooty mold (black coating) on the leaves. Terminal leaves may become yellow and distorted, and dieback may occur. Infested plants are usually growing in sheltered locations, such as against south facing walls. The mealybugs may be found on lower leaf surfaces and stems. Adult mealybugs are about 1/8 inch long, and covered with white wax. The body margin is ringed with white wax filaments, with the last pair over 1/2 the length of the body. Immature mealybugs have short wax filaments. This mealybug feeds on pyracantha, holly, yew, and rhododendron. There are two to three generations a year, and the immatures over-winter on the bark. Inspect plants for beneficial predators such as ladybird beetles. Some immature ladybird beetles may resemble the mealybugs, but move faster. If the mealybug problem persists, ant control may be necessary. Ants feed on the honeydew secreted by the mealybugs and protect them from parasites and predators.

A third possibility is Thrips, Thrips imaginis. This insect is a seasonal pest, causing most damage in mid to late summer. Signs of damage include silvering of the foliage and distortion of growing points and flower buds. The underside of leaves may be covered with excreta of the insect, which are like brown tar droplets. There are no effective specific biological controls and thus control can be difficult to achieve. Thrips are preyed upon by ladybirds and lacewings but these predators cannot control thrips in plague situations.

A fourth possibility is Rhododendron Gall Midge, Clinodiplosis rhododendri. Clinodiplosis rhododendri usually over-winters in the soil as a prepupa. Pupation occurs in spring, with the adult midge emerging just as the hosts begin vegetative growth. There may be two additional generations yearly corresponding with flushes of rhododendron growth. Eggs are laid in clusters on the undersurfaces of leaves that are emerging from buds. Larval feeding causes a downward and inward rolling of leaf margins. Larvae mature in about seven days, drop to the ground, burrow in and make a cocoon.

I forgot to say that I have several plants that have a couple branches like this most years and I do nothing. I hasn't spread to any other plants and doesn't get any worse. So even though I mentioned all kinds of possibilities, I personally don't think it is a significant problem. If it does get worse than find out what it is and what you should do.

rhodyman, thank you for the exhaustive analysis on possible causes of the distorted leaves on my Goldbukett.

I believe Leaf Gall is not the cause as no egg-shaped formations have appeared on the leaves yet.

As for the Long-tailed Mealybug, no honeydew or sooty mold has appeared on the leaves.

Thrips are not very likely as I have not found any residue on the underside of leaves, plus ladybugs usually do a good job in my yard.

I will look carfully for eggs of the Rhododendron Gall Midge when new growth appears to see if this might be the cause.

Meanwhile, I have found a webpage where a picture of very similar leaves could be found under
'6. Frost burn on new growth'.
I have attachged a link to the page.

Let me know if you believe this could be the actual cause.
In any case I will follow your advise and wait and see if the situation worsens.

Here is a link that might be useful: NON-DISEASE PROBLEMS

As Harold Greer says on that page:

"Aphids wlll cause the same deformed appearance, as can high heat during critical cell development stage."

In my case I think it is the heat of summer hitting the new spring growth before it hardens off. It just hits certain plants and does it just about every year.

Your leaves may look similar to #6 frost burn, but they're definitely not the same.

#6 is not just Frost Burn.

It is

1) Frost burn OR
2) Aphid damage OR
3) Summer heat on new growth

Specifically,
6. Frost burn on new growth - Even light freezing can damage cells as new growth is forming, causing the cells to develop improperly and make the leaf look deformed. Aphids wlll cause the same deformed appearance, as can high heat during critical cell development stage.

I am now quite sure that the problem appeared during a critical stage of new growth (leaf) formation and affected only selected branches of the rhodie. The most probable cause is high heat (direct sun) hitting this side of the plant. I have decided to wait and see. However, I could easily notice on the stems underneath the damaged leaves very healthy looking dormand buds. Wonder if I should prune above them, maybe the new growth that will come out will not develop the same defeormed leaves.

I wouldn't worry about it. In another year you shouldn't even notice it whether you prune or not unless it does it again.