For the mixer policy to be reversed, the legal environment would have to improve a lot. I think that one of these would have to happen:
 - Some mixers win their court cases.
 - Congress passes laws which explicitly protect mixers.
 - The administration ends up being extremely pro-privacy, better than 99% of politicians in office.

It'll take at least a year before we have a good idea of what the new administration will really be like, but my expectation is that they will only be ~10% better than the Biden administration in this area. I would be surprised if they dropped the case against the Tornado Cash devs, for example.

The Trump administration could be a lot better than I expect, but they could also be a lot worse. I think for example that the Trump administration might be even more aggressive on sanctions (especially against Iran), and they might therefore see financial privacy as a threat to their sanction power. There are also several reasons why the Trump administration may want to restrict cross-border payments generally: to allow for financial repression in response to a debt crisis, to reduce the US's huge net international investment position deficit (which is often a major issue in the minds of Trump-aligned economists), to tariff services in addition to goods, or to control the value of the dollar. Such restrictions on cross-border payments would also put them in opposition to financial privacy.

The Biden administration clearly wanted to move as close to banning crypto as they could get away with, so it's definitely good that they're gone, but it's not as if Satoshi has just been elected president. The Trump administration has some interest in pleasing their crypto donors, but that can be achieved mainly just by getting prices to go up. They don't much care, and don't have to care, about privacy, disintermediation, decentralization, etc.