You're right - I guess I should have said it was Mosep who was retconned into the light-haired nimban, not the dark hair version was retconned into Tawss.
However you want to describe it, thanks to the SW.com article
, I always thought Mosep was supposed to be the dark haired guy. Now, he's the light-haired one for some reason.
Like I said - either way, I'm happy to buy any cantina or Jabba Palace alien they make, even if they can't keep the names straight anymore thanks to all the changes over the years.