Let's start with:
1. mary.moodle.net → marydev.moodledemo.net
2. research.moodle.net → research.moodle.org
3. prototype.moodle.net -> https://docs.moodle.org/dev/Prototypes

then:
4. demo.moodle.net → sandbox.moodledemo.net
5. demomaster.moodle.net → sandboxmaster.moodledemo.net

then check that all is working fine (reset scripts etc), and if so do:
6. school.demo.moodle.net → school.moodledemo.net
7. schoolmaster.demo.moodle.net → schoolmaster.moodledemo.net 

[Insert from sub ticket - _Remove above list of old user-facing moodle.net subdomains (EXCEPT school.demo.moodle.net as hardcoded into Moodle mobile app and can only update upon release in either August or November 2019 - until Juan Leyva gives go-ahead)]

and:
8. qa.moodle.net → qa.moodledemo.net
9. qamaster.moodle.net → qamaster.moodledemo.net

Note: All the above can be done immediately or at any time before September 2019.

Finally, to be done after 15 July 2019:
 10. learn.moodle.net → learn.moodle.org
 11. learn.next.moodle.net → learn.next.moodle.org

Please comment "1, 2, 3 done and ready for checking" etc. before proceeding with further redirects.

Note: This issue is only about redirecting subdomains to new subdomains. Deletion of moodle.net subdomains will be in another issue (for after we have updated links everywhere).