Definitely agree the fact that Simone proposed a third category is worthy of discussion.
I've seen commentary on her tweets from both sides of the divide not pick up on the fact that some trans athletes really oppose this, view it as transphobic. It didn't sound like Simone was aware of that, or that when swimming tried one there were no entries.
World Aquatics says no entries have been received for the new open-category races at the Swimming World Cup event in Berlin.
www.bbc.co.uk
I've seen a lot of assumption, from people with the full range of views on the subject, that once Simone knows this, she'd be in favour of allowing people to compete in the category of their chosen gender rather than sex.... but she's not actually said that at all. People are filling in the gaps, and as you say, that's quite different to what she wrote.
It will be interesting to see if she says more at any point. I suspect the potential ramifications of having in the same exchange told a five foot five woman that she's man sized might mean she's been advised to leave it for now, as that was not a particularly wise addition to the discussion.