I'd disagree.
A Biden / Democrat administration pushes for unity and increased corporation with EU allies. A Biden administration could also seem "soft" on China on the surface but they are more crafty, strategic and better at the geopolitical game. Like others have said before, if Biden wins there will be more tension in the SCS and China would need to be careful of EU countries like UK, France and Germany especially around trade and economic times.
The Trump administration is aggressive to the point of recklessness. Trump is not only driving internal divided in the U.S. (race, left wing vs. right, gender, etc.) but he is also creating a divide between the U.S. and traditional allies like UK, France, Germany and even countries like Canada and Australia.
IMO had Clinton won instead of Trump, China would have been in big trouble because Clinton is a China hawk and her administration would have handled COVID and race relations magnitudes better than the Trump administration.
Not really. Biden attempts to "neutralize" China with Multilateralism might not work for several reasons
1. Past Obama's attempts to build a multilateral coalition failed to deter China's activities in the South China Sea.
2. Each member of the said coalition might have different agenda, it is difficult to completely synchronize them. For example, South East Asia governments do not really share U.S concerns regarding human rights, HK National Security Law, and IP theft. As shown in lack of solid outcomes from both EU and ASEAN regarding China.
3. A swift change of strategy will give China the perception that the U.S cant handles "stick match" e.g. trade war. This perception will embolden China.
4. Building a new coalition will consume a lot of political capital, no lest because of Trump's alienating allies.
5. China itself is in the process of building her own "iron brothers" and cement her influence within UN bodies.
6. Biden might be distracted by other crisis, possible next flashpoint include Belarus (Putin might annex it), middle east (Arab + Israel might attempt to do a preemptive strike against Iran due to fear of Iran military buildup post embargo) or the Mediterranean sea (Greece vs Turkey)
Clinton is a China hawk and her administration would have handled COVID and race relations magnitudes better than the Trump administration.
On the other hand, I believe Clinton will focus more on Russia and the Middle East compared to Trump. Also, I read a memo written while Clinton was the Secretary of State in Wikileak(IIRC), it said that they are kind of sure that Taiwan would be economically swallowed up by PRC sooner or later and there is no value in preventing that.