An alternative near future is that what you're describing is used to undermine/rightswash strong copyleft free software for use in proprietary products, while owners of proprietary software (and big movie studios and record labels) start protecting themselves with EULAs forbidding ingestion of the works into LLMs.
Another possibility is the one others sketched, where truly user-controlled models are legislated away.
Do we really believe that Rockstar would be ok with someone feeding GTA6 to a hypothetical LLM and get a "free" reimplementation out? If that world were to come to fruition, I'd maybe buy the "best thing to happen to free software" story. Otherwise, my bets are on "complete and utter stomping of small IP rights holders in favor of giant ones". In that world, free software is in real trouble. Together with indie artists and writers. I lament how many people don't seem to take this scenario seriously.