If Facebook were to implement a language model inside the platform now it would raise a lot of privacy issues. By publishing free to use models they can rely on others to do the work of training the society into using such tools at mass scale. So by the time they adopt in in all their services there will be much less backlash.
Not just for the engineer-hours, but for the endless VP/PM political meetings arguing over this approach or that.
Way cheaper to let the market decide, and then reincorporate the winner into their products. A winner which happens to already be based on a semi-compatible tech stack.
