So, the last time we played, we ended with carousing, as per usual, and got the result that a bard was now friends with a party member. I was asked who the bard was, to which I cleverly responded "uh ..." (I later went back and added a new NPC bard to the players setting guide.)
I'm thinking that I should proactively create a bard and a wizard (the other result that shows up a lot on carousing tables) for each town the PCs are likely to wander into. This actually feels like a good worldbuilding exercise, making them all distinct and appropriate to the town where the carousing takes place. They wouldn't appear until the carousing roll summons them into play, but I wouldn't be stuck flatfooted in future.
How does everyone else handle "and now there's a new NPC" result on random tables?