Why do people get namechanges? For some it's simply because they have a shit name and they want a better one, but there are plenty of people that get namechanges to get fresh starts and wipe away bad history. It makes it easier for them to slide into the community if people aren't aware of who they are when they first meet them (e.g. Kyure/lumpysolo).
It'd be handy sure and it's not a bad idea, but the same thing could be accomplished by just asking the guy whether they've changed their name before... We know the site devs have a tricky relationship with work, so I'd imagine they'd only be implementing more necessary/impactful ideas.