Can frostbite reoccur years later

Answer 1

It can come back if the part is exposed to severe cold again.

The damage may be more severe on previously injured parts. This is partly because the scarring can reduce the sensitivity to heat and cold of the affected area (so you don't notice until too late) and because scar tissue can have diminished blood flow.

Frostbite will not come back spontaneously, although past scarring can cause other issues, such as phantom pain (due to past nerve damage) and even necrosis if damage to blood vessels was severe enough (though any damage that severe would likely lead to tissue death in the first place).