I responded to another commenter with a detail I deliberately left off, which is my direct manager was one of the team members to leave. The next higher up manager oversees all the engineering teams in the company and has been hands off.
I'm certainly spooked by this situation, though as you said this could be a significant net win given I will eventually have a majority the domain knowledge (if I'm kept on this current team), it's just not in my brain folds yet.
Getting additional perspectives is super helpful, so thank you!