That is how Open Source is supposed to work, I don't understand why everyone is thinking that this is some kind of huge discovery. Since both the MVICore and MVIKotlin repos are Apache 2.0, Badoo could simply pull in any improvements from MVIKotlin in if they wanted. They could ask their ex-employee if there was any interest in Badoo officially maintaining the project.
There are about ten other paths I could suggest that go with how OSS projects can and should work. None of them involve sending legal notices to your former employees to "transfer" the repos.
All I'm seeing here is that some person at Badoo/Bumble with little knowledge of how OSS works and a lot of lawyer time to throw around has made this move, and lost them a lot of goodwill from potential future employees.
