From what we've seen, I don't think Rewind erases memories so, for Izuku, he might have gone from 'suicide in front of All Might ' to '8 y.o in front of mom' and Alec may or may not have been expelled from the body. . .
Izuku should have the Original body, don't know what might have happened with any clones, replicas, duplicates or otherwise grown body.
If Alec is still alive and present in BNHA, he is probably mourning right now, since he already ia resigned to the existence of the Source Wall and the consequences thereof.
This last extra also gave some conclusion of Alec's involvement to both Eri and Izuku's storylines, which means that can be a good place to stop.
As always, the final decision is in the author's hands.
Thanks for the normal chapter and the extra!
~~Fish_Brained_Idiot