If the model turns out to be inaccurate: A) Change the architecture to reduce costs to the point where it becomes profitable at an attractive price point for customers, or B) Move on to the next idea.
It's not that complex, and more startups should be more realistic about profitability.
That said, I get your point that if you can create a model that gives you a good sense of future profitability, you are in a better position not to die as a company.
This provides a signaling of value, creates a real business relationship, and directly contributes to the lifespan of the vendor.
A free model doesn't really tell their business if there's actually demand and if people actually value it when supply is "infinite" when in reality it isn't.
Guess a high price with some research for similar things and lower it iteratively. Def. see what sticks.
Also they could combine this with discounts, such as if someone preallocates capacity for X month, they get f(X) % discount.
They should build a core customer base. Solicit feedback about what niche feature they would happily pay for.
For example here's a GitLab issue that I think people would (might?) use: https://gitlab.com/gitlab-org/gitlab/issues/15536 (provide a "lock service" or a queue with max concurrency gate and launch pipelines / jobs)
I ask because I see a lot of these dismissive comments on HN which end with "open source it" - and that doesn't seem like a super constructive piece of advice to a new startup team.
FWIW, at my current company, an analytics company, about five years ago, we made it clear that no matter what data we collected, if you leave the service or we shut down, we will get you all that data to take with you in a very reasonable format.
It's always risky to invest in a new service, but sometimes risks bring great rewards, and I think it's helpful if you're giving input, to try to make it constructive.