Fowlers issue here was always utilization and expectation. The team that can fit him on the second pairing or with a true #1 will love him. The Blues appear to have that, so they’ll likely love what Fowler brings.
This has always been the issue with the Ducks. Fowler has been utilized incorrectly for most of his career. Throughout though, Fowler provided good, quality minutes, strong offense, and a great attitude.
It is not surprising to see him playing well; I personally expected him to improve. In fact, I would argue most of the players on this team would improve playing on stronger teams. Better structure, coaches, players, vibes, etc... - all of it adds up to an environment more conducive for success.