Except if the messengers happily collude with you, which Facebook does - they have a website (can't remember the link) where network providers can get IP ranges and other information to enable "zero rating" for Facebook's properties.
FWIW, if my information isn't outdated, FB requires users of the mobile partner portal to be actual mobile networks; airlines are not invited. I worked on this for WhatsApp before I left in 2019, and the airline text only free messaging did not fit with the WhatsApp special pricing/zero rating offering. Afaik, FB doesn't work with airlines on these offerings; the offerings started before I left and were a surprise to me when I was still informed about all the partners (because I had to add them to mailing lists and do other integration work)
And if they allow large IP ranges, one could try to spin up a virtual machine on the same cloud provider as the messaging platform.