What is "in-place" about this? According to the docs you'll have ~10min downtime and you'll loose table statistics which is exactly what happens when you run pg_upgrade manually.

The biggest problem with all the cloud providers is that you won't know exactly when this 10 minute downtime window will start

I guess the only advantage here is that you don't have to do 9->10->11->12->13->14 like in the past and maybe that was one of the blockers Azure has. AWS allows to skip some major versions but 9->14 is not possible.