Samsung just announced that a few devices will start to get one UI 3.1 over the next few months:
A90, A70, A50
But without the Google discover integration, which is pretty sad (the default Samsung daily or free or whatever they call it now is just a laggy, ad-filled garbage - you should probably turn it off). I hope Samsung will bring the discover feed integration, especially after Google's botched android 10 gestures whereby to get a usuable experience one has to use the default launcher. Also, i have one UI 2.5 with October 2020 update on my a51 5g still (even tho it should get security updates every quarter, which means I should have got the January update weeks ago) and NO SM-A516 model globally has one UI 3 (apart from the SM-A516V but that has a different cpu and is a different phone). I hope Samsung are planning to give people who don't have 3.0 already a non-delayed and quick upgrade to 3.1 considering it isn't bringing many useful features, and they have already made people wait for longer then they should for security updates on devices like a70/a51 5g.
I cant lie, I know nothing about the M series. To be honest I thought Samsung were being serious when they said they'll streamline their phone range but just took out the J series and switched the letter to an M. Sometimes Samsung can be unpredictable lol 😆
Well, in a sense it's worse now. Before it was just the J and A where the A was distinctly higher end and better, now (yes many of these devices are region specific but why??? can't it just be one device globally for that price bracket?) we have the F, A, and M series. A is technicially higher end, but some M models are better specced and Samsung just came out with the F62 with a flagship processor for the same price as a71 in India.