Taking out the "training a model" part, the same thing could happen with a human at the company.
But again - this doesn't stop me from continuing to write and publish in the open. I am writing for other people reading my content, and as a bouncing board for myself. There will always be some shape or form of actors that try to piggyback off of that effort, but that's the trade-off of the open web. I am certainly not planning to lock all my writing behind a paywall to stop that.