I do not think this is a coincidence that tension between the US and China raises every time Trump has political issues, just like Russia suddenly finds ennemies when Putin faces discontent, or that Turkey fights kurds 10 times stronger when Erdogan feels threatened.
Pointing an ennemy is a great way to get away with many things, and works very well with all kinds of publics.
Obviously he wants to finish a deal w/ China before the elections so he can use it as an example. Not everything is a conspiracy.
Not to mention he seems to permanently be in a state of political crisis with his adversaries in the US. They've been rattling the impeachment sword since he got in power.
Or maybe it was planned to happen before another round of negotiations and the timing is a... coincidence? Hard to believe in these anymore.