They’re basically trying to get rid of vaultwarden and other open source forks. I expect they’ll get a cease and desist and be removed from github at some point in the not too distant future if they don’t make some changes. I have a vaultwarden instance and use the bit warden clients. Guess I’ll need to look for alternatives in case Bitwarden decides to get aggressive.
DMCA is a tool for suppression of free information. It doesn’t require evidence that you’ve made a good faith effort to consider fair use or other legal complexity as it’s meant to take down the information before that is settled in court, but most commonly used to suppress information from a person or group who can’t afford to fight it in court. Microsoft’s Github has a history of delete first without risking their own necks to stand up for obviously fraudulent takedowns much less ones with unsettled law like APIs/SDKs.