Resolution: Not A Problem
Affects Version/s: None
Fix Version/s: None
We found another case where a user without ADMIN permission tried to connect to Phoenix and failed because they tried to obtain the namespace descriptor.
This one was coming out of the CREATE SCHEMA IF EXISTS call, kudos to Sergey Soldatov for getting to the bottom of this one.
My existing test case had a bug which was masking this failure condition. Fixing that reproduces the issue.