I don't think using the argument that people that bought this years release would be in uproar if they did, as any sort of proof that CGI is not been redone.
People buying the movies now, know that this release isn't the 20th Anniversary edition. And, I don't know if the release next year will have CGI redone or not, but, if they are going to do it then next years version would the one that they would do it for. It would be a great way for them to get people who normally don't spend money on extras to buy the anniversary edition. And it would give people who bought this years edition a reason to buy the Anniversary edition. Or should I say another reason to buy
because lets be honest here, a lot of the people who are buying this years edition are fans and will probably end up buying next years edition anyway.