So Dylan has the memories of his ancestors? Mentally hes not a kid then?
Poor Will. And he's an adopted noble so he can't even really consider going off and having a nice gay romance with the boy he accidentally fell for, even if he were to decide he wanted to... That's rough.
The possibility has been introduced, at least. They explicitly said "sometimes you get memories, sometimes you don't"—it's now officially up in the air as to what his actual mental age might be. It could still be exactly what we think it is.
I'm also wondering now is whether the protagonist counts as one (with her memories of her previous life, even if it was in another world)—and whether that will matter in any way if so.