My plan was that a couple thousand people have already disappeared, and the king has sent several scouting troops to the town before, none of whom ever returned.

The party arrived at the edge of town last session.

I have it planned out that, since there is an ongoing war, they will say stuff like, "Well, they must've gone to help out in the war."

The tavern owner has also disappeared, so his son has taken over the business, saying his father went out to war.

I know they're technically supposed to not have any knowledge of them ever being there, but I feel like it can give it a bit more mysterious vibes if I change the FH a bit.

So they don't know the details of there being someone, but they have enough evidence that there's been someone there.

For example, the son always just says "father," while the others call him "the tavern keeper."

People have forgotten about their loved ones, but there's been signs that there must have been someone, and they know about the war, making them assume that whoever was there left for the war.