Reading carefully what they posted above, it appears that from ASIAIR 2.0 on, earlier versions of iOS than iOS 11, and iPhones earlier than iPhone 6 will no longer be supported by ASIAIR.
On the Android side, only Andriod 7 or newer will be supported, as long as they also have more than 4 GB of RAM.
On Oct 1 2022, ASIAIR will switch to "Stage 2," i.e., Android 7, iOS 11 and iPhone 6 will also be dropped.
Keep in mind that iPads that can run iOS 11 are also capable of running iOS 12; the ancient iPads can be upgraded. The iPhone 6S has been around since 2015 (the iPhone 6 came out in 2014); so only Apple phones from before 2015 are unsupported.
It appears that ZWO has decided to set a more reasonable base-memory limit for Androids. The 2GB (the recommendation that was set by Google in 2020) and lower memory sized Android devices are practically unusable with real apps. iOS has always been better with memory management, and has no constraints (albeit, one of my large iPad Pros does come with 16 GB of RAM).
Comment: the iOS TestFlights are still on the v1.9 track. But it appears that Android betas have already switched to the v2.0 track. It appears that ASIAIR is already prepared to stop supporting Android devices with less tha 4 GB of RAM in the next full release.