Question Author
Safe to say that right now it's unclear. Sky changed their story a couple of times. Possibly multiple factors involved -- a breach of the Ministerial Code is not necessarily a sackable offence in the present Government, but if there were some other point of dispute then Truss might have felt there was no choice, and anyway it was convenient.
Either way, clear that Truss has no grip. It's sad watching this, frankly -- especially because I can't see how any Tory PM can plausibly call an Election -- it'd be suicide.