I agree that this G2 framing is a nightmare for many countries that are U.S. allies in the region—that the U.S. would acquiesce to the framing of a G2 with two great powers, the U.S. and China. Clearly, some of the atmospherics from this summit led to that impression.
The silver lining to this—and a caveat for those who are more concerned about it—is that there are multiple actors in the U.S., such as Congress, the Senate and different policy actors. I'm not convinced that some of the transactions that appear to have been made at that summit will be long-lasting. I think there's deep China skepticism in Washington.
If you want an example of this, the freedom of navigation operation that just happened in the South China Sea was a couple of weeks after the summit in China. There are examples of how the United States is not going to abandon all of its activities meant to deter Chinese adventurism in the region. I think that will continue.