no, there won't be an updated credits list for ANH:RHD. There will only be additions if its for people who are directly involved with anything i need help with when doing the HD version.
In fact the way the credits list is created will be totally changed when i get around to ROTJ:R. It will feature only people who have had a direct input in the edit by working on it or helping out in some other way, but not just for inputting suggestions. The credits list is becoming longer and longer each edit, with many posting a comment just to get on the credits list. It's become a nightmare to keep track on everything so it has to get shrunk down. It will now only have a general "thanks to everyone at OT.com....etc" sort of thing.