I don't see what Trump has to gain by leaving Moore to twist in the wind: irrespective of any personal shortcomings, Moore would be Trump's strongest ally in the Senate. That's all that matters.
Trump should just fly to Alabama for yet another runway campaign stop and embrace Roy Moore while he's there. With Trump's visible support, Moore will win by a much stronger margin than what the polls are showing now and thereby frighten the GOP senate leadership from any attempt at his expulsion.
Moore is a loose cannon. Trump said one of the reasons he backed Strange was because he was an automatic yes vote on anything he wanted.
Yes, that calculation makes sense. The Senate is full of Republicans from the right and center who vote nay as means of grand standing. Trump didn't want another Rand Paul, Ted Cruz or John McCain. He wanted someone who will keep his mouth shut and vote yes.
