This looks great - I've been looking into debezium for a similar idea but they don't natively support views which makes sense from a technical pov but is rather limiting.
There's a few blog posts on attaching metadata/creating an aggregate table but it involves the application creating that data which seems backwards.
Would be huge if materialize supports this out the box. I believe it's a very useful middle ground between CRUD overwriting data and eventsourcing. I still want my source of truth to be a rdbms, but downstream services could use data stream instead