It looks like https://www.facebook.com/messages is effectively the same thing.
When I'm trying to focus on something I have Messenger.com installed as a desktop app, so I can see when my friends message me without seeing a slew of FB notifications. facebook.com/messages has the notifications, there's no way to turn them off. This move feels like FB is trying to force me to choose between their engagement bait and seeing messages from my friends.
Hopefully that means they are still using/supporting Rescript.
yeah but messenger.com was nice if you've blocked the facebook.com domain to try to use less social media.