The CHECK constraint doesn't need to directly track that information- it should have a dependency on the column in the table and that's where the information would be recorded about the current collation version.
Just to have fun throwing odd cases out, how would something like this be recorded?
Database default collation: en_US
CREATE TABLE t (c1 TEXT, c2 TEXT, c3 TEXT,
CHECK (c1 COLLATE "fr_FR" BETWEEN c2 COLLATE "fr_FR" AND c3 COLLATE "fr_FR"));
You could even be really warped and apply multiple collations on a single column in a single constraint.
