That’s the corporate promise for now, but there is no Ulysses pact guaranteeing they’d support it forever if the financials don’t line up any more, so the second-best guarantee is if there is a strong self-interest incentive that would remain to be the case even in 20, 30 years? They mentioned that they need scale and so offers generous free tiers as proving ground, but would that incentive stay the same after a few decades?

You do realize you can say that about literally every service in the world, right?