I can understand adding some friction to discourage using Bitwarden without 2FA, but requiring it seems very wrongheaded to make it mandatory. I've been using 2FA on Bitwarden for a while and it adds a lot of friction and made me very nervous that if I lost my phone that I'd be locked out of literally every account I have. I mentioned elsewhere (link below) that I have solved this issue for myself, but people shouldn't be required to jump through these hoops and introduce a greater opportunity to lose access to their accounts if they should lose their phone.
https://news.ycombinator.com/item?id=42853696