it probabably will releaf ... after the leaves are totally dried as well as the little ( TINY) stems that they are directly attached to..... the whole thing, leaf and tiny stem, should pop off easilily don't do anything til then and don't force it..under the removed area should be two new green buds ready to go ..Now here's the thing ..being out in the sun may crisp out the new leaves that come out too...but you really have no choice .
There are many here that may disagree with your area prep but I don't think that had anything to do with your leaf crisping just the hot sun and these plants were probably under shade cloth before ya got them ... bare root and partial bare root are a problem this time of year and I have come to the conclusion often best put in pots til fall or next spring.
One word of advise I'd cut back on the watering a bit and don't add any more fertilizer ... your tree has no leaves and i don't think it needs that much water at this time just keep it moist not wet.Others here may have additional or differnt advise but this is what I do and i had several trees do exactly the same both in pots and planted out with this hot late spring David

I for one am not an advocate of bare rooting Japanese maples at any time other than when fully dormant. Their roots are extremely sensitive to disturbance and the trauma of bare rooting, shipping and replanting at this time of the season is sufficient to send any JM into shock. My preference would have been to pot it up and baby it for awhile before planting out in the ground in full-on sun, specially in mid June. My nursery advocates extreme care when planting even well-established containerized or B&B maples at this time of year and our summers are notoriously late to start and NOT hot when they do arrive, if rather dry.

I think David's advice is sound. Without seeing your soil and planting conditions firsthand, it is only speculation but the amending you have done in "heavy clay" soil may be creating a poor drainage situation - too much moisture remaining in close contact with the roots and not percolating down through the soil level. Generally, if working with a heavy soil it is recommended to dig a very wide but shallow planting hole adding no amendments. Plant the tree high, backfill with the soil you removed and add the amendments as a mulch to smooth out to the top of the roots. This wide, dished planting hole will allow for adequate drainage without creating a bathtub effect of a deeper, amended hole.

Personally, after such a short period of time in the ground, I'd be inclined to lift the tree and pot up into a container where you are able to more closely monitor the amount of sun and water it will receive and give some much needed TLC. Forget the fertilizer - stressed plants are unable to metabolize much anyway. And you can add me to the list of those who think that SuperThrive (or SuperJive, as a friend refers to it) is pretty much just very well-marketed snake oil. The active ingredient (primarily B1) is present in such an infinitesimal amount and then is further diluted by water that it is providing virtually no measurable benefit to the plant.

Thank you to both of you for your very prompt and helpful responses. I examined my little maple yesterday evening and found that the tiny trunk and all branches were quite red, with some healthy green at the base of the trunk just above the crown. Indeed, when I looked under the tiny branches, I saw all over these tiny little red dots that looked to my eye to be new buds -- very much like the little swellings of new growth you see on roses in the spring. I have decided for now not to replant the maple into a pot, and will leave it where it is for the time being.

Thank you for your advice and encouragement.

Allan