The newest update pushed forward the Generation 8 egg moves. I have two qualms with this and will use them as the basis for inciting this change/suggestion.
1. In a competitive standpoint for servers rather than single-player you now have players who managed to get a hold of Egg Moved pokemon, such as Close Combat Pinsir or Pursuit on a multitude of pokemon. This creates an imbalance in the competitive scene as now accessibility has some dictation on what you can have and what you might face. These previous egg moved pokemon will begin to dwindle in stock as players forget about them or leave servers, but players who have them will still always hold a slight to large competitive advantage depending on the situation. This is something that is currently happening, just today is the very first day of it.
2. We are allowed to have pokemon who are not included in the Generation 8 games. Main point in this is that it doesn't make a terrible lot of sense to have a very decently well incorporating and diverse pokemon mod/game in this regard but for some reason get extremely narrow in regards to movepools/egg moves/etc. There's even a setting to allow for "illegal shinies" which means that somebody put forth the effort to look up event pokemon or another that can't exist with certain moves AND be shiny. With that kind of effort, why would we not have all the egg-moves or even just movepools from past gens be available?
I apologize as this is partially a rant, but I also believe it is a good suggestion as it gives for a more encompassing mod/game where players from all generations of pokemon can have an understood experience that isn't narrowed down by a very simple choice.