This is a behavior change for 16.0 that appears to be missing from the documentation (i.e., I can't find it). Here is a description of the behavior change.
In 16.0 databases (newly initialized in 16.0 or upgraded to 16.0), the SQL text is stored in catalog tables unparsed with all identifiers quoted. Further, in these databases when the server parses a statement that is known to be unparsed, the non_keywords option is ignored. These changes ensure that identifiers are treated unambiguously in 16.0 and all future server versions independent of what new keywords are defined.