Very adroit of you to note there sir. Very adroit.
It is interesting that the sex allegations with the porn star whore with Trump 12 years ago are dismissed as 'old news' and irrelevant by virtually the same people who went into frothing berserker mode over the allegations from 40 years ago made against Moore.
Recall from the primaries, Trump has some media allies, and this is 'old news' in the sense that the story is a rerun.
Moore, by virtue of standing his ground over the Constitutional provisions in Alabama which restricted marriage to between one man and one woman, has few, if any, mainstream media allies where homosexuality and that agenda are prominent, and fewer who would speak up for fear of their careers. The allegations, never before made, were fresh and a surprise: "Breaking news", whether fabrications to nuke his campaign (most likely) or not.
He also had the Democrats out to 'get him' to win the election, the anti-Christians after him, the lavender lobby, and even the GOPe who didn't want anyone who would stand on principle to the extent they lost their job loose in the swamp.
While the Democrats may see that as a springboard to attack Trump from, they just don't have the open blue on blue (red on red?) assistance to the extent they had with Moore, so while that perfect sh*tstorm may have sunk Moore's ship (and that was still fairly close), they won't 'get Trump' with that, just maybe cause some domestic discomfort.
I would guess that Melania is savvy enough to not let any fracture be seen, and as this is old news (revisited), even on the home front that this would likely not cause any problems there, either (any issue there already resolved and ancient history for them). IOW, this round has nowhere near the explosive force in the news.
Add in that the allegations against Moore specifically targeted a large number of his otherwise supporters because they hit at a vital moral issue, with or without proof, mere doubt can hurt, and that Trump supporters to a great extend really don't give a hoot what he did or didn't do, and the whole tempest will die in the teapot it belongs in.