[zaarn]

That is if completely unmaintained and under much worse conditions.

Bacteria in the permafrost have been found to have been repairing their DNA for almost half a million years. IIRC they aren't really active, they don't reproduce at all, only a very minimal level of metabolism is maintained to repair occuring damage in the cell.

The Worms could be similar. Being frozen, they merely shut down everything but the absolute minimum of metabolism, likely powered by minute temperature differences or incoming light from the outside or many of the other options, just enough to keep the DNA and cell intact, the worm itself would likely be considered dead in it's frozen state.

But they are waiting.