Something like that 
Omicron is so different to any of the previous versions that it’s almost a different virus - its lineage must have started sometime back before the original Wuhan Flu. And yes it will mutate, and the mutations that survive will depend upon what selection pressures we put upon it.
The boffins are only now just starting to admit that the least-virulent evolutionary pathway is to just leave it alone. That probably would have been true to begin with. The longer we try to keep it out (if indeed that is actually happening - personally I doubt it) the more “immune debt” we build up, which will have to be repaid with interest.