Considering that it’s the DfT who are funding them and the DfT who decide everything these days, the views of any GWR manager are somewhat irrelevant.
The senior team at GWR (who are the Directors, btw) need them to work so they can get the Turbos westwards. There are some very vocal opponents to the 769 fleet amongst the drivers fraternity and the seat arrangement is totally unsuitable for the build of a few drivers at Reading, which is why GWR is redesigning it.
Air Con or Air Cooling is a good subject for debate, given COVID. There isn’t too much difference between the two so I’m not sure what the beef is here, apart from providing another excuse not to like them.
If Reading depot want to lose the North Downs work to Southern, they can keep on disliking the 769 idea and then eventually the DfT will lose patience.
Meanwhile, Network Rail still haven’t given GWR a SOC, which means they can’t get off Reading depot.