
It's not done the present neo doesn't get to experience anything other than painful memories. It's a very painful feeling cause you know you weren't with him but your past self was and you don't even know what happened. IT'S JUST REALLY NOT DONE I FEEL BAD FOR NEO

Don't worry he is slowly getting the memories of the past that he changed. Like remembering that Senpai used to wake him up (to have sex) every night- Pg31. Also remembering the other two members of the club Senpai belonged to, who sent them their wedding invitation.While in the actual timeline Neo never knew Senpai belonged to the paranormal club let alone know the members.
In short he remembers everything about his actual timeline but also getting flashes of memories of his altered past.Eventually getting all of the memories of the altered past. It is just how the time travel works here.
If you are worried(like me) that it was the other(past) Neo not the original one who lived happily, remember how he said :"You would wake 'ME' up. Even when 'I' was asleep". Meaning HE was the one who lived a different life.
ヾ(❀╹◡╹)ノ~

I am happy if my reply really relieved you. I understand that the time travel creating a different future might be upsetting(in certain cases) since we are aware of the real events. The time travel may erase the actual past and pain for other characters and even for the main character(sometimes) but we still remember and that is what causes pain.
So lets just accept the new past as if it were a better reboot to an original (but bad) movie ╮( ̄▽ ̄)╭ヾ(❀╹◡╹)ノ~

From what I understood he doesn't. But I am secretly wishing that he does. I mean the past Maki (in the altered past) was aware of the mini ghost of the adult Neo right? It was because of the conversations that Maki had with ghost/adult Neo that Maki revealed his bindings because of his family. And after ghost Neo confessed his feelings Maki too finally confessed to Neo (both the adult & past one, I think. Since he never uses honorifics during his confession).
But there is also this possibility that ghost Neo when in the altered past was acting like a guardian angel (so only his influence was felt) . It would be like in the new past, adult Neo played the cupid(invisibly). Where the new teenager/past Neo never met adult/ghost Neo but under his influence/guidance properly met Maki, got to know about the spirits that made him sick, the paranormal club and finally developed feelings for Maki.( ̄∇ ̄")
Idiot kutta uke I just wanna kill you shala khanki just got die