Anything that reduces friction for a user to get started with your product has the potential to be a good thing.

But if your goal is to make money, and not just generate usage, I can see some possible problems with this approach. Not having a way to circle back with a user is bad.

Also, if someone truly needs a solution to the problem you are solving a signup form will usually not stand in their way.

It would be interesting to A/B test the entire user lifecycle to see if this approach has impact on the metrics that actually matter.