okay, so I remember the kids early on are like "how do we still have internet?" and the reason is basically just "magic" because they have a stable connection when in hte medium the whole time. I mean hypothetically the Trollian and Pesterchum servers should've been crushed by meteors, along with all the internet infrastructure.
also, despite being coded in different languages that shouldn't stop them from being able to communicate cross platform, it would just require code that sends the message in a data packet for the other client to unpack