As to the references to weight and A/C, I found a report from 2017 on a proposal for a gondola system in Austin, TX that stated that adding A/C to the cabins would reduce the capacity by 25% (from 8 to 6) because of the added weight.
As to the actual issues with the heat, I'm much less worried about it. I'm going to defer to those who have explained on many sites how this system is used throughout the world (it's just new to us) as a method of urban transportation and this issue (as well as many others fretted over) are not issues in those places. In particular, I've seen many who have referenced actually being on the same or similar system in Hong Kong, where the heat is just as oppressive (some have said it can be worse), and they had no issues with the temperature in the gondolas.
Honestly, what most excites me about this project is just adding more efficient transportation. I really hope it's a success and is expanded throughout the resort. The more busses can be avoided, the better.