Less due to the paint I feel, and more due to the message that it might represent due to the species involved. After all, Monkey is one of the nastiest things you can call a person of color and having Ash paint his face darker to befriend and act like a monkey pokemon is not a good look in the slightest, so it's totally understandable that they're skipping the episode for now, either forever (it's filler like a majority of the episodes in SM so skipping it will do zero to the main plot unless the Passimian group comes back) or until the animators in japan can reanimate the episode to have ash only wear a basic costume instead of getting his face painted on, since they had to have an XY episode reanimated to change Ash and Greninja from being crucified by Team Flare to sedated and in a less questionable position due to CN not allowing it the original display.

This totally makes sense, but it kinda is a bit ironic since the animators in Japan have literally gone to crazy lengths to reduce any kind of major bans like this, from removing japanese text and replacing it with gibberish (save for the Z moves which are blanked outside of Japan so they don't have to rewrite it in every language) to being more tame with some things in general and checking with the US producers on some things. I have a feeling that TPCI thought this episode would be OK before DXD stepped in and said no after it was made, but that's just my speculation.