I'm planning to add some post-events after Lv100, just like what we have in original Pokemon games, like refight the battles again but at higher difficulty with new rewards. I have some potential images ready for these but I didn't went further for it.
We can implement this, but this will be at the end of my list of priority updates and fixes... and we'll return to this afterwards.
Anyways, this is another tick to the checklist of potential content to work on! Thanks for the suggestion, I hope you can look forward to it!