Prior to electronic communications people used couriers or mail. Wanderers in the same vein as the Medieval traveling minstrel would go from town to town delivering information. Recall that all throughout the Renaissance scientists continuously communicated with each other in this fashion. Sometimes they would congregate at various academies. We must not forget public bulletin boards were available for tacking notices.
I clearly remember in the 1960s subscribing to publications of all sorts. A lot of information moved in that manner. The electrostatic copy machine was invented in that time frame; and, certainly boosted the ease of disseminating information.
The telephone modem became a very common method of moving a lot of information around in the 1960s. That was accomplished over dial-up landline communications. With the advent of hobbyist computing came the BBS, or bulletin Board Service: A dial-up center for distribution of information over telephone modems. These centers moved information an software in large quantities. Your computer probably contains a telephone modem.
The FAX machine has been around since the late 1890s.
In the 1980s I helped organize and operate a public UFO Forum. Our information came through BBS services, wandering minstrels, books, magazine subscriptions, and paid lecturers from out of town.
Fear not. It will always be possible to communicate with like minds.
I’m thinking we also need a low tech solution.
Maybe do what our Founders did and meet up at local watering holes.