Sorry if this has been asked before but I couldn't find an answer or do a fair search of the forums before.

Long time returning player and I've noticed no one has their Profession displayed. I found what I think the setting is but it doesn't appear to work.

Flag ShowProfession is on and it still appears that my Profession is hidden. Was this a permanent change with some legacy commands remaining behind or am I missing part of the process?

The title system has expanded enormously and profession titles are rarely used these days.
If you check out what titles are available to you now, you might well pick one out of the skill set, and after you've been playing for a bit and have access to them, one from the bounty set or one that indicates storyline involvement.

Normally if you want to see a profession of someone you need to use PROFILE. (On a quick sample of 10 I see 4 titles with LOOK, 3 storyline and 1 profession, though all 10 have profession visible in their PROFILE.)

It isn't hidden by default.

They consciously hid their title or changed it to one of the other options. If it is still one of the many profession alternate ones, you'll get a hang of what they do. Or you can look up the title on the wiki (https://gswiki.play.net/mediawiki/index.php/Title) or watch them cast or do something specific.