"Reality has a liberal bias" .

Sure, every author has a bias. But a fair selection of human written sources will be pretty balanced (of course, given the ratio of languages, surely western models will have a western-christian bias - presumably Chinese models less so, but this latter I have no way of checking).

If you train specific stuff on top, or deliberately filter the sources (e.g. Tiananmen square), your model is deliberately less honest on that topic. Grok is probably the worst in deliberately filtering and training "out" specific stuff (to the point where Elon posted stuff that "they will 'fix' the models" real output when it said something true but remotely liberal). Claude and chatgpt definitely have some similar stuff, but mostly to protect themselves (e.g. suicide prevention, not saying slurs, etc). I don't think the two is comparable (reality bending vs basic etiquette-kind of not saying everything out loud)