Holy crap, this is going to break half the world. Deprecating NTLM is like banning all the standard locks on all doors and mandating that you can only use biometric-based locks that scan your iris — and then just hoping people can do it. This is going to suck if they actually try to enforce this and do in fact take away NTLM.
I don’t feel like writing a whole long post about NTLM — what it is and does — but Microsoft is going to nuke a whole lot of shit when they do this. Currently, the documentation for how to transition away from NTLM is terrible and nearly-unusable, many applications and devices do not support Kerberos (the newer alternative to NTLM), and many companies will not be able to comply with this at all for at least 15-20 years.
This is going to break a vast amount of stuff. I need to schedule a very long vacation when Microsoft does this craziness. Don’t want to be anywhere near this pointless disaster.
This is yet another example of fake security that makes many, many things harder or impossible to use for extremely little gain. It just makes life roundly more difficult “for your own good.” Really, though, it is being done so you have to buy more Microsoft products and get further locked in to their ecosystem.