Wow those are nice graphs. I thought there were only 2 strains of the virus reported so far, but this seems to indicate many more, unless I'm confusing 'strains' with a better suited word like 'variations' or something. Idk, this isn't my forte but would appreciate correcting.
These are variants sequenced from individuals. There so far is very little diversity in these sequences. The branch lengths are very short. There is isn't anything yet to describe any qualitative difference.
The amount of variations are concerning. Seems it'd be likely to mutate into a different strain. If that happened it would be ravaging. People that have already gotten sick and have lung damage could potentially catch the new strain and be even more at risk since the weaker. It'd be like the 1918 influenza pandemic where the first wave wasn't that bad relatively but the subsequent waves did a lot of damage.
