They're probably 'safe' trt but I'd imagine they're well past their best and no longer as 'tasty' as they once were. If they've been in there that long and not been eaten personally I wouldn't bother.
2-3 years is a long time to be in the freezer, trt.........3-6 months I would say is ok on certain foods.....I would bin 'em, otherwise you could have a dose of the Leon T's methinks........not nice at all..:0)