A few weeks ago, I planted several Gomer Waterer rhododendrons. They had been in containers at the nursery since the past spring. Approximately 1/4 of the new leaves resemble the one in the attached pictures. They appear disfigured and have "puckers". This leaf has a "burnt" tip. Most of the afflicted leaves do not have a "burnt" tip. Is this a disease, or might it be due to the long period in a container before planting?
We don't think that this is a disease, but likely a sign of water stress.
If they had been in the pots for a long time, they may have been pot-bound.
Plants that are pot bound often have circling roots and solid rootballs that tend to be dry and keep the shape of the pot.
At planting time, it's best to cut vertically through the rootball at intervals and straighten out some of the roots within the hole.
If you didn't do that, we'd recommend doing it now for best long term results.
As newly planted broad-leaved evergreens, we'd also suggest continuing to water them right up until the ground freezes for the winter. Give them a 2-3 inch (only, more is not better) mulch layer, but keep it away from direct contact with the trunks.