Yes, you would need genomic sequencing to highlight the mutations.

PCR can give issues in detection for this very reason.

Most antigen-based tests will continue to work, because most are targeting the N antigen of the virus. And so far, the N antigen remains conserved in these variants.

For molecular tests, whether or not they continue working will depend on the number and location of genes that the test targets. The new variants have mutations in the S gene that have been found to impact some assays targeting this particular gene. However, if a test is targeting one or more conserved regions other than the S gene, then the test can be presumed to detect these new variants.

If they are correctly assessing via genomic sequencing, they can provide insight into number and dominance in a region.

GENOMIC SEQUENCING IS REQUIRED TO ASSESS MUTATIONS IN THE FIRST PLACE.

WE KNOW THIS.