There is of course much more involved than just altar rails since kneelers could probably be provided where necessary to fulfill that need. There may be some rule though that does in fact require the rails to separate off the sanctuary area. I’m not sure about that one.
There is the matter of the altar itself. Would each church being asked to provide a TLM have to install a second altar? Or somehow move them around after each Mass? Realistically, most churches build since Vatican II are not set up for the logistics of the TLM, either in altars or altar rails.
I would tend to think that as a practical matter it will require that certain churches that do have the altars and altar rails available, as well as priests trained to offer the liturgy, would have to centralize TLM’s rather than having them in each parish.