I haven't done anything with regards to anomaly/trend detection yet, but it's planned. Not really sure where you see a database (TimescaleDB) fitting into that though?
I feel that we could probably use a time-series database to reflect our streams as 'last observed state' type collections as well as do the aggregations that we need to feed back into anomaly detection.
I'd like to also use something like that to create a 'heat map service' where you can feed a property/window/range and get back scalar for color coding and possibly a slice of values for sparkline type UI.
Without getting hands on, though, it's hard to say for sure.