Update cloud-tiers.md

Downgrade tiers is now allowed and self-service

Author: chloecdc

docs/cloud/manage/cloud-tiers.md

@@ -196,11 +196,8 @@ Single replica services across all three tiers are meant to be fixed in size (`8
 
 ## Upgrading to a different tier {#upgrading-to-a-different-tier}
 
-You can always upgrade from Basic to Scale or from Scale to Enterprise.
+You can always upgrade from Basic to Scale or from Scale to Enterprise. Downgrading tiers will require disabling premium features.
 
-:::note
-Downgrading of tiers is not possible.
-:::
 
 ---