What exactly are you saying? I already stated that the anime doesn't religiously follow game rules, but is still loosely based on how the games work.
It's a truth that in the anime, pokemon have movepools too and can learn moves in ways different to how you teach it in games (Pikachu and Volt Tackle as an example), but to base any kind of claim solely on a Ditto is a bit illogical. They also somewhat change how some moves look/function in anime, so the same can just be said about Ditto (I mean, game ditto can only transform into the opponent it faces up until USUM where a sidequest showed Ditto even transform into humans just like in the anime).
Overall what I said still applies, anime rules are only loosely based on the game rules, but other than a Ditto, a pokemon in the anime is still limited to knowing only 4 moves at a time (and you can google evidence of that everywhere)
At best, things have been less clear in the very 1st season of the anime(possibly johto season too), but then again, lots of things that used to be there in gen1 are changed in modern day so yeah (e.g. having real life animals appear in the anime alongside pokemon, referencing existing world locations etc)