is there a chance that new mons will be added?
Many people have tried adding new Pokemon but it is a lot of work! https://gitgud.io/argonvile/monster-mind/ I include instructions for it on the gitgud.io site which hosts the source code. It is about 50 steps and includes a lot of drawing, animation, writing, and programming.
https://discord.com/channels/441368427295145985/441387973754486795/1095430210108...
ONE person on the discord has added their own Pokemon to the game, I think it was an Espeon! They uploaded an SWF with the new Pokemon in it. It's not 100% finished but apparently it has nice art and dialog!