Let’s start with the inversion. When she’s inverted, the base of support is below the shoulders, so that’s legal.
Now to the transition from the extension to the pike. I can understand why it’s being questioned. It’s a vertical release that ends up in a non-vertical position, which is illegal. However, the way they do this, I think it’s legal and they could even make it more clear to be legal.
The bases are releasing the foot slightly as they switch their grip from the extension (fingers on the outside or toes of the foot) to the pike (fingers on the inside of the foot.) They do this before she is out of the vertical position, so that is a legal release. Then, she transitions to the pike while in contact with the bases, making that part of the transition legal – no release. I would make it more clear and avoid issues as the coach by having one of the bases catch with her fingers inside the foot on the front hand (thumb pointing forward) or have her make that grip change while in the extension, before the transition. That way, that hand is in place on the foot the entire time and there is no release at all.