Transparency is key. If the filtering is transparently disclosed on the results page with a note to the effect of "We've excluded results we consider to be Russian propaganda", then it all feels on the level and understandable, if not agreeable. Without such an upfront disclosure, it feels slimy and manipulative.

It's the difference between hiding results, and hiding that you are hiding results. (Yes, I know it was disclosed on twitter. It should be disclosed on each results page, like Google's "some results were omitted because DMCA etc" disclaimers. That is precedent for this sort of disclosure.)