Moderation is unfortunately a fact of life given the abuse non-moderated forums are frequently exposed to. I don't regularly see questionable moderation practices perpetrated. The few times I have seen things done that registered as questionable to my estimation, a bit of persistence tends to get the message to take root and bear fruit with at least a few curious minds generally after an indication that intellectual curiosity is piqued and fruitful non-flamebait discussion may be a result.
I'd also use the search function to see if said thread still exists. I haven't seen much straight up disappear, but stuff can travel to the hundreds in ranking surprisingly quickly as the overall conversation on evolves.
Is there any more detail you'd like to offer on the specific instances of material you feel are being unfairly buried and any guidance you may have received as to why they may have been? Generally there is at least a guideline violation or two that can be worked around.
Also, as always, remember the audience and platform are not ever guaranteed to be receptive to what you feel is important. That's an occupational hazard of the of information transmission, and the challenge to be overcome to get your message out there.
Failing any satisfying resolution, just keep at it! They can't stop the Signal, and given enough time, enough other people will pick it up to make sure it bubbles up somewhere. Just maybe not today.
Anyway... No matter what direction things go in, we're all still watching.