A post from EA details a new patch that's now available for The Sims 4 on PC and consoles. This describes changes to address "instances of wholly unacceptable content that has been uploaded to The Sims 4 Gallery." This does not go into specifics, but according to Eurogamer, this addresses an "increase in Nazi propaganda and anti-Semitic content." Here's the official description of the update:

We are aware of and have seen some select instances of wholly unacceptable content that has been uploaded to The Sims™ 4 Gallery. Our team has reviewed, and made critical updates to, the profanity filter to help prevent this from happening again in the future. We are grateful for the community’s vigilance in helping us identify these inappropriate uploads so we can maintain a safe, creative environment for our players. We will continue to do our part by quickly taking down objectionable content that surfaces, identifying and removing repeat offenders and regularly reviewing the profanity filter in case any updates need to be made.

We encourage players to continue to use the “Flag This” button on The Gallery to report any offensive uploads or comments.