Thank you for your continued feedback, we have not forgotten about this ask. This feature request remains on our backlog. We will share an update as soon as one is available.
if you have an existing post that you want to show in a different channel, you can edit the message and cross-post. This will add the top-level post to the different channel, but will not include the full set of replies. We will keep this request in mind as we evolve the cross-posting feature in the future and update if the status changes.
Details on cross posting can be found here: https://support.office.com/article/cross-post-a-channel-conversation-in-teams-9c1252a3-67ef-498e-a7c1-dd7147b3d295.
This is currently in internal testing rings at Microsoft, and the feature team is targeting a release to the public in early Q2.
~Alex & the Teams team
Due to a priority shift this request has slipped to the backlog. I hate to bring bad news. I will continue to provide the feature team your feedback and votes.
Hopefully this will move back up in the queue soon.