How likely is it? Let’s hope discussion is allowed:
Within the field of population genetics, the phenomenon of mutational meltdown—in which a population may become extinct owing to the accumulation of deleterious mutations—has been well studied both theoretically and experimentally. The key to understanding this effect is a consideration of the efficacy of natural selection. Because there are many more ways to disrupt rather than to improve genomic function, the vast majority of new fitness-impacting mutations are deleterious rather than beneficial.
Jeffrey D. Jensen and Michael Lynch, “Considering mutational meltdown as a potential SARS-CoV-2 treatment strategy” at Heredity (Edinb). 2020 Apr 6 : 1–2. doi: 10.1038/s41437-020-0314-z [Epub ahead of print]