Myth: "the ride sits there for months on end with nothing being done to it"
Reality:
Many 'coaster style' rides have the ride vehicle removed, and taken to a maintenance workshop for maintenance. This would explain the lack of visual activity, whilst still being more than 'nothing'
Extended downtime is usually an indication of an unexpected delay or issue - for example, a fault found during routine testing that was not anticipated requires further investigation or rectification. It can also be because a specific part needs to be replaced that wasn't anticipated, and has to be manufactured \ ordered from overseas.
Some maintenance work is carried out outside of hours, due to workloads, or the impact such works would have on guests during the day - such as noise, or dust, or the need for large plant and machinery to move around the park's guest access areas
But GD hardly makes any discernible noise if you aren't close by. Roachie said remove TOT, and use the tower for GD upgrades, which would still free up the space without getting rid of the tower.
I couldn't say whether it has or hasn't. Fact is that the tower was built by intamin, so in theory they could supply suitably modified upgrades to suit. In theory the rolling stock could remain, and just a new seating arrangement could be attached with minimal modifications.