I've been working in this for a long time my career started in 1983 with my engineering degree. What you are saying is true that excessive reverberation times are problems in big rooms. In fact we just corrected one of these problems in a church where the decay times were greater than 7 seconds. This is where I stated Large vs. small rooms have a different set of problems. Small rooms the bass is dominated by standing waves which isn't the problem in large spaces.
There have been many studios I have been in an measured that are from neutral. There are a LOT of studios around the world and they do not measure the same. Just think about how many put their monitors on the metering bridge and the acoustical problems it causes? Yes, the better studios typically use baffle mounted speakers or speakers on stands to solve this issue. The better studios place a greater emphasis on the room too. But, there is no standard. Some are lively others dead and anywhere in between.
The dubbing stage is a small theater where the final mix is created. TV dubbing stages are often smaller and more numerous, movie ones there are probably less than 20 worldwide. That is the area to replicate, not your local cineplex which can be varied between theaters. Here is what a good dubbing stage looks like. Click on the link for the Kurosawa Studio.
Here is a quote right from Dolby Labs
"In small studios with basic acoustic treatment and geometry, the frequency response of a speaker system below 100 Hz is dominated by the modal response of the room. Strong low frequency standing wave patterns can be observed in small rooms. Therefore, it is very difficult to achieve consistent low frequency response from multiple fullrange speakers in such limited space. One solution to this basic acoustical problem is to set-up the monitoring system using a Bass Management System. If the multichannel set-up uses small or mid sized monitors, then a subwoofer should be included in the system and by using active electronic filters and crossovers, one can extract the low frequency information from the main channels and route that information to a single subwoofer feed. The LF cut-off of the subwoofer in the room should be close to 20 Hz. Also, the crossover low-pass filter should be very steep so that midrange information is sufficiently attenuated. The ‘bass-managed’ low frequencies will then originate from one single source that can be placed in an optimum position in the room. Therefore, the Bass Management’s basic and main goal is to ensure that the entire audio bandwidth of all channels can be accurately monitored."
I've taken classes at both these places (THX and Dolby) as well as many others. Bass management is always emphasized and even exists in larger theater spaces. But, in the larger spaces it is more about capability then solving standing waves. Like many surrounds can't play full range in many theaters, they often only go down to ~50-70hz.
You are obviously educated but need a little more understanding of small room acoustics. The links I provided before would be a great start. I would encourage you to look at bass problems in small acoustical spaces:)