I don't think you should equate giving you an email address with the willingness to become a user of your product, once it exists. If you end up building this product, it would be interesting to hear about your "conversion rate" for these early emails.
And on the flip side, I personally am very reluctant to give out my email address to an entity that is essentially a company that doesn't exist yet, with a product that doesn't exist yet. Even if I'm very interested in the product in theory. (In this particular case I'm not in your target group.)
Finally, here you write that you are essentially only collecting emails at the moment, while the submission button on the website says "Get Early Access". That is very vague, but to me it suggests that you are at least actively working on development and will have a beta or at least an alpha sometime soon. So I find this very dishonest. Dishonesty is not a great look for an entity that harvests emails, or one that hopes to provide financial services.
All in all, I don't think this is the "right" way to launch this product at all.