Update from my side: for me it worked to change both device and Siri language, restart the phone and change the language for both back, restart again, charge and connect to wifi and wait. It works again, although I miss the button for „talk to siri“ in control center, but that doesn‘t bother me. Just weird.
Edit: noob me forgot to restart my iPhone first, the „talk to siri“ control center button reappeared and everything works again like Beta 1.
Edit 2 7th March: the new Siri animation disappeared again this morning...