Facebook has been using it internally for a long time. It would make no sense for them to rename the tool for open-source release just because a naming conflict exists, unless you'd prefer they just not release it at all?
I am familiar with most of the other tools mentioned here (e.g. SonarJava) from my time doing Java development outside of Facebook and never had a collision in my head because this project is not actually a library or tool for Java. It's a standalone Electron app that works on iOS and Android for debugging purposes, the only Java part is incidental in the Android app (and could be Kotlin or C++ or whatever you want).
That's a bad example. Gerrit is not a new name for Reitveld, it's a totally new implementation (with similar inspiration). And both of those were publicly released under those names.
Your underlying point is quite true, though.