It's an interesting question. We held a national referendum on Donald Trump last November. The overall consensus, taking everything into account including the allegations against him, was pretty mixed, and he only ended up squeaking by on a technicality. A different voting system might have returned a very different result.
It's possible Matt Lauer would fare better if he were subject to such a referendum. Or he could fare worse. The people complaining about Lauer, and the people firing him, are probably people who would have voted against Trump. We might assume they are somewhat consistent. Or we might not. After all, it seems NBC knew about Lauer's behavior for years without acting.
But of course Lauer's employment isn't subject to national referendum. Instead, NBC must consider the reaction of their own staff, the reaction of their target audience, and the value that Lauer brings to NBC. Obviously, asking "but Trump?" won't mollify the NBC employees who have been harassed by Lauer. It might mollify some of NBC's viewership, but the trade-off might not seem worthwhile to NBC.
In a sense, I think this is part of the same phenomenon as the recent flurry of statue-hate: Anti-Trump Transference. A lot of people are very upset about Trump's election. But they're largely powerless to actually do anything about it. So their rage and frustration gets transferred to other things. They can't depose Trump. But they can topple statues that have gone without public outcry for decades. They can't remove Trump over sexual harassment allegations. But they can remove any other public figure they have power over. Which turns out to be a surprising number of prominent, powerful, and influential people on the left. People whose abusive behavior was quietly tolerated for years.
It's not the swamp Trump talked about draining, but it is a swamp, and it is being drained. Ironic!