This is a psychology question and i think we have seen the results happen.
RuneScape graphic updates,
Magic the gathering cardborders,
Any big changes in anything really.
People are incredibly emotionally attached to DDO the way it is. And people do not like change in general let alone change in their favorite thing.
There will be a massive outcry, a bunch of people will leave but most of them come back. Then everyone accepts it as the new norm. In a couple years people will begrudgingly agree it probably was a good change.
In any case, never gonna happen. We can only hope someone makes a new d&d game that is like DDO.