MasterGwydion
Emperor Mongoose
I don't know that I would call a recompiling of the rules a new edition, as long as that is all they do, put all the rules in one place for each rulebook.Well currently there are three different editions of MgT High Guard with different rules in each.
They can call the next one an update if they like, but to me it will be a 4th edition.
Edit: Personally, I think the whole idea of editions is outdated. Editions only really matter for books in print. Digital books can be changed and updated without having to buy a whole new book, so changes could be done on a smaller scale for free, or they could hold the changes for one larger update and then charge a lesser price than buying a whole new book. It is a lot easier to change things today than 40 years ago.