Didn't see a tab to report issues at https://github.com/PlayFab/PostmanCollection so figured I'd share here!
The multiplayer/ListMatchmakingQueues entry gives a 404 response until changing multiplayer/ portion of the URL to match/
The v2 Postman collection is also no longer importing headers properly, resulting in needing to add e.g. Content-Type: application/json manually to each entry.