Things that are most certainly going to be implended are:
-Bnet Features. All Blizzgames use them and thus classic will aswell.
-Things that reduce support and gm activitys such as loot trade, restore or other things that tie to that
-Bnet Currency and tokens, because tokens were a way to counter goldsellers. There are people wo are willing to pay money for gold and if Blizz doesn't provide it, other people will with all the negative consequences like account hacking.
-Bnet shop with character transfers and faction changes. Same reason to counter payed leveling services.
So even without touching the gameplay or graphics there will be changes that were made to solve issues that directly negatively impacted the gameing experience or illegal actions or led to higher support costs. We can most certainly be sure, as Blizz is a company that tries to reduce costs (like all do) that these feature who were proven to do so, will be implended.
No matter what.
Oh and BTW, to all of these nochange advocates: Most of you were playing on servers that provided these features aswell. Character boosts, payed exp increases, payed item loot and so on.