Again, as people have pointed out, its a lot of work and it doesn't exactly achieve anything. Pretty sure there was a thread on this already, and the simple response was 'if you are getting a namechange and want people to know, then tell people you are getting a namechange beforehand'.
And yes, its a lot of people to catalogue, along with that extra little bit of useless work a staff member would have to do every single time someone gets a namechange.