It’s probably a proprietary connector made specifically for Yamaha, or Yamaha made it themselves. It’s loosely based on car connectors from what I can see, but I don’t think you’re gonna find much info about it.

I’d just go in “guns blazing” with this thing. If there is a replacement for it and it’s fairly cheap I mean. If not, I’d try and pry the silicon off with some of my DIY tools for these sorts of situations.