I think Cat is right that starmer/his advisers think this statement is a clever walk of the tightrope - not actually expanding on the manifesto position (for which Labour got plenty of criticism from TRAs as well as GCs), just emphasising the bits this audience (Pink News) wants to hear and not saying the other bits (stronger single sex exemptions) out loud.
And to be honest it's probably fine with 90% of people who might consider voting Labour, most of whom don't think this issue particularly important either way.
He can either continue to walk a wobbly line, pissing off everyone who feels strongly but not making any sort of impact with anyone else
Or he can go full TWAW/full self-ID and lose a lot of Red Wall/GC feminist votes
Or he can go full GC and lose all the Corbynistas and kiss goodbye to ever recovering labour's lost Scottish seats
He's in a bind - this issue is just a microcosm of the massive problem Labour has. None of its ideological constituencies are big enough to get it a parliamentary majority, and Labour can't find positions that bring its constituencies together. They had the same problem with Brexit.
Don't get me wrong, I don't think he's very good. But as cat says, if he goes the next leader will be full-on TWAW. I'm keeping my membership for now, if only to vote in the next leadership election...