Well, she's not wrong that we need more influential people fighting back against this latest push in the global coordinated effort to put an end to communications privacy. It's really quite alarming how little attention it seems to get most of the time. Civil society seemed much more robust when it fought off similar attacks in the 1990s. I do hope that the "VC community" isn't our only hope.
But of course Signal can’t interoperate with another messaging platform, without them raising their privacy bar significantly
Signal is supposed to be free software. You could probably manage to interoperate at least with other operators of actual Signal-Server instances, if you wanted to.