Bitrot means degradation of physical media containing digital data, not really anyting to do with bugs appearing in code that is introduced into a new environment.
> The Jargon File, a compendium of hacker's lore, defines "bit rot" as a jocular explanation for the degradation of a software program over time even if "nothing has changed"; the idea being this is almost as if the bits that make up the program were subject to radioactive decay.
https://en.m.wikipedia.org/wiki/Software_rot