Yep. There aren't many cranes in the world tall enough to work on TTD's 420' top hat. They're massive. Thus, they're expensive to rent.
Any work on the tower short of maintenance tasks like repainting would require cranes of that size to be brought in. Be that adding to the height, taking away height, re-tracking it, or removing it.
If they're already going to the expense of bringing in the extremely expensive and hard to schedule cranes, it would seem to make more sense to just tear down the entire top hat. But that's the most valuable part of the structure, at which point, what's the benefit over removing the ride entirely? All the ride really is, is some shuttle track on the ground to get you around, the launch, and the top hat. Keeping the top hat necessitates keeping the launch, and almost vice versa.
The hydraulic launch system is notoriously unreliable overall, and has been a safety issue from the start. Replacing that with the LSMs many of us suspect will be installed would do wonders for safety and reliability. That's a notable change in the ride experience, even more with the new trains to go along with it.
There's always the chance of the ride being expanded, but the most likely scenario is a full upgrade of the electrical and mechanical systems (control system, launch mechanism, etc.). Modifying the top hat requires similar expense to just removing the ride entirely and wouldn't significantly improve the ride experience. It's not a detriment to the ride. The structure overall isn't a safety or reliability issue thus not a top priority for investment. Everything else is.