I think the name is plenty different, nobody will mistake LibreSignal as being the same as Signal. That's as if Microsoft goes LibreOffice and OpenOffice are trademark infringements of Office (insofar as you can trademark the word "office" anyway).
As for the politely asking, yeah that is still banning. If you banish someone from a country, they can still physically walk into the country. They're just not allowed to.
Nobody has been banned from anything. People have been politely asked not to distribute 3rd-party builds of Signal using their name and their servers, and that's it.