Responses
He wouldn't. There's a reason they have him bond with Aki's ex and have him say that. He's learned that whether or not he lost his ex or even loses Ue in the future, music is something he loves and it shouldn't go away from him. I think he's fine with mourning Yuki but choosing to love Ue wholeheartedly in the present.
uenoyama u green flag bastard (affectionate)
also, before this i saw comments "if yuki come back alive, would mafuyu leave uenoyama for him," and i decided to ignore the what ifs thank u very much