Loop looks interesting, especially the live-updated content sharing across channels.
I just tried it out for knowledge management, however the feature set is lacking to the point where it's not worth investing any more time just yet.
It's missing elementary features for knowledge mangement and documentation - e.g.
- hyperlinks to other pages.
- draft+publish lifecycle.
- document attachments/in-line preview
- theming, styling and user-defined templates
- code-blocks and in-line styles (e.g. "term" highlighting)
- tabsets and other non-paragraph based blocks.
- etc etc etc.
There is evidently work to be done before this gets out of beta, and answers to other questions have indicated the existence of a roadmap.
Is it possible to make public enough detail of the roadmap and the planned feature-set so that IT departments can plan around it?
I think a lot of the things you're looking for are in SharePoint. Loop isn't trying to replace anything, it wants to sit alongside other established Microsoft products in their ecosystem and act as a bridge between them. I've been doing my own evaluation, and the product Loop most closely resembles is Atlassian Confluence. There's even a Jira connector to bring in Jira issues for 2-way sync. But it's not even a complete replacement for Confluence: Loop isn't a document management / content management platform. It's not even a super great replacement for OneNote.
My own (unofficial) comparison - may be inaccurate.

But, where Loop shines is its simplicity. Not everyone needs a do-everything solution. I imagine it's more for brainstorming, meetings, ad hoc collaboration, and fun stuff. Just like Planner is a scaled down alternative to Project Online.
There are some features shown in the announcement video that don't appear to be live yet, e.g. dragging documents into the treeview navigation, bringing in content based on keyword search, copilot, etc. I'm very curious as well about Loop's roadmap.