Pretty sure this was a 'what if' and was purely academic. The study was on 'sustainability' not 'what would you do with this old ride' and can be found here, provided google's linking works properly.
The same study references this, but the proposal was for the Sydney monorail, and they simply suggested it could be done here too.
They expand on the idea further:
The trouble with this idea is either it is an incomplete circuit, or they spend a lot of money building a walkway that goes out over the carpark. There's also a question of how wide a walkway could be, built on top of the narrow monorail supports, and whether it could handle the different forces put on it by a moving crowd.
Either way, i think these proposals were entirely academic - they were done in 2019 before the pandemic and before most of Atlantis was built and i'd suggest their currency and relevance today is questionable, especially since they made up only a small portion of the overall sustainability proposals the university actually set out to do.
Nope.
The entire reason Arkham remained standing as long as it did was because they didn't need the space for something else yet, and it wasn't unsafe to remain as it was.
If they decide Monorail is gone, then as soon as Sea World needs monorail space for the next attraction, it'll get knocked down - though this doesn't mean the entire thing will go either.
If they cared about heritage - we'd still have Viking's revenge. The bridge. The Ski Show. Heritage really doesn't play a part here (and for the most part, it shouldn't, save for the extremely enduring heritage attractions the likes of LPS Wild Mouse or Scenic Railway.