TL;DR:
Microsoft are bringing back the Site Permissions panel to Teams channel sites in SharePoint, displayed in a read-only mode. Site owners will also be able to access and make changes to the site sharing and guest expiration options. Due early to mid-July 2022.

Details:
The site permissions panel will be available on Teams channel sites and can be viewed by all users. However, this panel does not allow permissions to be edited, it is read-only. Microsoft will add a banner at the top of the panel to indicate that this is a Teams connected channel site and permissions should be managed in Teams:

For Private Channel sites, site owners will see both the Site Sharing and Guest expiration menu items below the permissions groups.

Shared channel sites will only display Site Sharing because Guest Expiration does not apply to shared channel sites.  

In the site sharing menu panel, they have made updates to reflect what content you can control sharing access to; for Teams channel sites you have never been allowed to share the site. The menu now has just two sharing permissions options (there are three on regular sites). Everything else remains the same:

Availability:
Due early to mid-July 2022.

Related Links:
Great recap: Teams (and its parts) and SharePoint integration | Microsoft Docs

Check status:
This message is associated with Microsoft 365 Roadmap ID 93240

MC390004