Stealth Omicron?

It's all too easy to think of Sars-CoV-2 having a vendetta against humans. The viral mutations arise, however, completely by chance. There are enormous numbers of replicating Covid19 viruses, which means that, somewhere on the planet, very many mutations will arise each minute. The vast majority of these mutations will simply never register. It appears, however, that a 'stealth' version of the Omicron variant has arisen (https://www.theguardian.com/world/2021/dec/07/scientists-find-stealth-version-of-omicron-not-identifiable-with-pcr-test-covid-variant). The highly transmissible Omicron variant is replacing Delta in many parts of the world. Fairly obviously, scientists and medics are very keen to monitor Omicron's spread. To do this, they use the PCR test to distinguish the variants. Stealth Omicron, however, lacks one particular mutation, enabling PCR to distinguish the variant. The virus acts like Omicron, being highly transmissible and having (at least) the potential to evade some immune responses. This version of the virus can, however, 'hide away' in the general viral population. The actual identity of stealth Omicron can be revealed by genomic testing but this is much slower than the 'rough and ready' PCR. Obviously, the virus doesn't do this deliberately. It does, however, mean that tracking of variants has just become more difficult. There are likely to be many more surprises associated with mutations of this virus. We really need to get Covid19 infections down everywhere!