Note that what I was promoting, a femtocell co-located with the charging location, has a range not much greater than about 10 yards (basically for the convenience of the vehicle occupant(s), but usable for emergencies by standing close to the post).

https://en.wikipedia.org/wiki/Femtocell

The default design of the femtocell supports up to 8 concurrent users, so there is no problem with someone 'hogging' the connection when somebody pulls in to charge.

For greater coverage, even something in the picocell range might be used for 'building' coverage, or for providing cell-phone coverage to passengers on the train at some locations. The feature in a 'commercial' femtocell that automatically does cellular handoff to 'the general network' would have to be modified as appropriate in the absence of coverage by a functional microcell or greater.

I doubt the mention of restrictions on "WiFi access points" would include the usual sort of WiFi bridge, which is a highly directional aimed pair of antennas to allow signal to pass wirelessly between, say, the charger and an attraction's office. Spillover from the ones I've seen have been very small.