I personally wouldn't see anything wrong with it....

Though, we also harvested about 30% of our rhubarb plant the year we planted it... and saw no ill affects. Now going on the second year, it has doubled in size and we've had to move a couple of other things to make enough room for it.

Some things that can turn rhubarb leaves brown are sunscald, stalk separation due to laying flat because of stalk crowding, or blight.

If the leaf appears diseased or the stalk is not firm, it should be removed from the plant, especially this early in the season.

If the stalk is not discolored and is juicy, it is edible.

The leaves will die naturally beginning in October or November and can be left on the ground until a general garden clean-up.