You've stitched together a variety of rather unrelated biological facts to construct not much more than a hypothesis.

For instance, just because we've found fragments of RNA in relatively recent cadavers doesn't mean that viable microbes and viruses are plotting our demise having been frozen and buried for tens or hundreds of millennia.

Just because something is theoretically possible does nothing to demonstrate its likelihood.

Don't believe me. Go read some more facts about actual work being done on this: https://www.npr.org/sections/goatsandsoda/2018/01/24/575974220/are-there-zombie-viruses-in-the-thawing-permafrost