Not true.
I have three devices. One has app 2.5 and other two have 2.4. I can see NFZs on those two devices without connecting to RC/P3. They were connected to RC prior to the 2.5 release.
I have summarized all findings to date on my OP for quick reference.
There is a post on the DJI forum discussion on geo fencing that states the beta was 2.44. Were the two devices on 2.4 at 2.43?
My purpose in asking is to attempt to determine the latest stable release of Go that won't contact their geo fence server when connected to the internet.