We (https://workflowy.com) built a try-first sign up flow, and a/b tested it against our current minimal signup page, which is a lot like those you describe.
Unfortunately, the try-first performed FAR worse. Not only did we get fewer signups (which we expected). The engagement rate for users who had tried first was significantly LOWER. Exact same product. Same first time experience. One group tried before signing up, the other didn't. They liked it less. Isn't that odd?
From my understanding, other services have experienced this same phenomenon. Why does this happen? It is hard to explain. It could be some aspect of our try-first design was flawed. But, my guess is that it's something psychological about signing up.
I had expected and hoped that the try-first flow would improve word of mouth. I think many do. But it didn't. So I'd encourage as many people to bring data to the table as possible. I've found through doing tons of a/b tests that metrics often don't obey my logic.