To answer your question, whether or not Thomas may have had a biological advantage is irrelevant for a number of reasons, least of all that gifted athletes will naturally possess a biological advantage over most other people.
There's a cisgender female South African runner who produces more testosterone naturally than has been deemed typical of other cisgender women. Should she be forced to compete on the men's team?
Not only do I think that progressives were in the wrong on this issue, I also think that they handled it so poorly that it caused a lot of damage to the movement and made the nation shift to the right on trans issues. It was a real “the emperor has no clothes” moment, and it may have honestly caused irreversible damage to the trans rights movement.
This isn't specific to transgender issues, but I really dislike the whole reactionary "look what you made me do" framing of their arguments.