If I encounter a travelling pokémon, is it gone forever?

Question

In PSMD, sometimes you find friendly pokémon travelling the dungeon by themselves, and talking to them will refill your HP, PP, and belly. After this, you are connected to them and you can use them in later dungeons.

But sometimes you end up finding several of these in one dungeon where you really don't need their restorations.

If you talk and connect to them, does that prevent them from appearing in any future dungeons? Should I only talk to them when I actually need their services?

Answer 1

Typically, they won't disappear, unless you do the stupid option of restarting the game, making everything disappear. Another way to prove this is how sometimes Pokemon are on missions different than yours, in which the 'closed' icon appears instead of the Pokemon. After a small while, they'll come back. This is typically the same as those you encounter in the dungeon to refill your HP, PP, and belly.