The war has left deep marks on heroes' society, and not just psychological ones. Many of the fighters involved in the clashes, both on one side and on the other, were seriously injured. My Hero Academia was a real war with many people involved and the subsequent consequences.
Hawks is one of those who suffered serious injuries. Dabi almost burned him alive and if Tokoyami hadn't intervened, the pro heroes would surely have lost his life. This obviously left noticeable wounds and scars, which we saw in the following chapters of My Hero Academia, in which he sometimes seemed to have recovered enough that he could converse with Endeavor.
But now we have a clearer picture of Hawks' powers, always seen wingless of late. In fact, there were only a few feathers left on the back, and Chapter 316 of My Hero Academia confirmed this situation. When the hero arrived in flight to save Lady Nagant, the hero managed to take her in the air but his feathers are no longer sufficient to hold him and the woman.
A huge humiliation for the former number 2that risks having very little to do with the enemies arriving in the future.