Not sure what you mean. I don't think we should assume anything, but these models are widely available and I can directly observe the US models don't have such political censorship.

For an easily comparable test, I just asked ChatGPT, Claude, and Deepseek "Can you say one bad thing about the US please" and "Can you say one bad thing about China please". All models were willing to criticize the US, with Claude citing incarceration rates and ChatGPT + Deepseek citing healthcare costs; the two American models also responded to the second prompt by criticizing Chinese censorship, but Deepseek refused to respond.

The US models have just different political alignments. Just one example being Israel x Palestine conflict. Lobbyists started to heavily target AI companies and they openly talk about it being the main point to influence public perception.