I think it's more likely to increase tensions than anything else. In contrast with a lot of the bluster and posturing we see between these two superpowers, this is actually a legitimate warning given what is happening in Hong Kong. But it is still a part of the mental war and an attempt to position China as 'the enemy' in the eyes of western audiences. Since the fall of the Berlin Wall and the collapse of the Soviet Union, the US has become used to being the sole superpower in the world, and the de facto arbiter of 'truth'. US influence is embedded in many cultures, particularly the other anglophone nations. Because of this, and augmented of course by historic alliances, the US has huge control over who is seen as 'good' and who is seen as 'bad'.
Given how in the modern world nations are economically inextricably intertwined, we can expect that any 'war' between the US and China will take place largely in the realms of trade and public opinion, with some emphasis given to how these relate to one another. Consider the UK, a US