Regarding the url change:
https://lists.wikimedia.org/mailman/listinfo/wikitech-l will change to <
https://lists.wikimedia.org/postorius/lists/wikitech-l.lists.wikimedia.org/%...
Is there a technical reason which requires including the list domain ine name? I would seem preferable by far to use instead: https://lists.wikimedia.org/postorius/lists/wikitech-l https://lists.wikimedia.org/postorius/lists/wikitech-l.lists.wikimedia.org/
and since all (?) our lists are using @list.wikimedia.org, it's not like we need the domain there to disambiguate it.
Cheers