Let me see if I can clear some things up here.
TL;DR version - The ticket in question had a mistake. Rather than put into a "waiting on other team" status, the ticket was accidentally put into "resolved".
Longer version - The CM handling the ticket provided a response that they had "triaged to the appropriate team" then the ticket was put into a status of "resolved" rather than "waiting on other team".
We have a number of automations that happen depending on various categories, statuses, etc. In regards to the "resolved" status on the community side of support, that automatically starts a countdown of 72 hours in which if a person does not happen to respond with a follow-up question/comment, the ticket is then automatically closed and sends out a notice, as happened here.
When a ticket is put into a "waiting on other team" status, that stops all automated processes within the ticket, effectively putting it into stasis until either a person sends a follow-up question/comment or an agent takes an action.
In the end, this was an unfortunate accident. I have re-opened the ticket, which is now in a "waiting on other team" status while I wait on another team to investigate and fix the issue (ticket 3928). Once the work on that ticket is done, I'll pop back in here and let folks know.
[UPDATE - The fix for this is now live. Please use the contact form to let our Community Support team know if you find an instance where it is still happening. Thanks!]