No, the proxy is a trusted CA and so it can mint a valid cert. It does mean they are not pinning their cert, but most apps do not. Even if it was pinned, you

No, the proxy is a trusted CA and so it can mint a valid cert. It does mean they are not pinning their cert, but most apps do not. Even if it was pinned, you just have to disassemble and modify the pin and you can still MITM.