I hope BF will realize the importance and potential.
I am not aware of the technical details of course, but I could imagine writing a script for automatic conversion of "old trees" to "new trees" is not too complicated. I am convinced that expanding the arena to the European fronts will prove to be beneficial for 1C and BF as well. In that case, taking advantage of the existing maps bank, sounds like a reasonable move, even if some tweaks and changes will be needed.
Personally, I would like to repeat each of the original TOW campaigns, taking advantage of the new features. In that case I would be more than happy to buy the successor title, knowing that I actually got a whole new title + the promised add-on through the back door... If some extra funds are needed for that - I will gladly pay :-)