actually, i wouldn't be surprised if trump tries to go left of biden in a few key areas if only to try to win the next election. i think he's under immense pressure due to mishandling the pandemic - he's not polling well at all, not that that means everything - and i suspect he's not above wildly shaking up policy in order to pick up votes, esp. in the critical swing states.
his party isn't in a position to throw up a challenger so the Rs are stuck with him, from my point of view: if desperate enough, who knows what he'll try?