In the thread I linked above, recursive commented that it would not be difficult to implement. Probably just comes down to adding a few lines of boolean checks and relevant code, at least to get the bare bones functionality in place.
I believe the concern lies with two things: AI and gameplay balance. AI ability to optimize would not be as sophisticated as humans (AI picks TR independently from any resource planning, whereas human would assess the best compromise resource/yield TR), and gating resource access to actual geography of the map, in any way, creates location bias and advantages to some starts over others, emphasizing RNG that the community has long sought to mitigate.
I don't think either of these amount to reasons not to do it, the former is just the way of most things in civ and the reason AI gets built in advantages, and the latter effect will be an enjoyable thematic outcome that shifts balance, rather than unbalancing the mod, imo. Still fits the "close enough" balance paradigm in my view, even if it does inch things over towards human.
It might be something to try adding a feature request for on git, to have it as an advanced setup option