I don’t know if you can do this through SQL but you can through a simple CL program. Display all of the user profiles to an outfile, then loop through the outfile and change the text for each one.
Technically, you could do it with SQL, but it would be more complicated than doing it other ways. Since user profiles aren’t part of the database, SQL isn’t closely related. You can create stored procs or other items to execute CHGUSRPRF commands, but why?
The suggestion to write a CL “script” that reads new texts from a file and assigns them with CHGUSRPRF is the right way to go. If it must be done.
Now, whether it’s a good idea… that depends on what info will be encoded in the text, I suppose.