I saw they were out of date as well, but Microsoft were (yet again) revamping their web portal.
Maybe now things are a bit more stable. Any one of us can edit as needed (just be sure to smudge any sensitive information if you are going to do this)
I'm still awaiting our Azure license so can't properly update this until that is working.
The main process now is:
1. Select Identity and then Azure Active Directory and App registration
2. Follow the existing instructions but make sure you use your own endpoints. Microsoft no long allow new app registrations from the generic endpoints
3. When you do the oauth register, check it again a few hours later and redo if it got confused. Otherwise you are good to go.