Somehow I missed the following post before creating this thread. Disposable sys-whonix persistent settings - #4 by deeplow
The problem isn’t that a disposable gateway would result in the same entry points but different entry points every time Tor connects. That lack of persistence in initial entry and exit points makes them easier for an attacker to correlate over time. Very counterintuitive and interesting.
Apparently this is an ongoing issue for the developers of Tails due to it’s lack of persistence - but their solutions to the problem aren’t applicable in Whonix because of differences in network configuration.