Yes, some members hold their titles dear.
When SitePoint migrated from vB many members had existing custom titles.
One such member asked about titles at Discourse.
When explained that he had a badge that he could use, but that if he tried it his existing custom title might not remain as an option should he want to revert to it (though if he petitioned Staff I’m sure one of them would have changed it for him) he in no way wanted to risk it.