I don't see it making much of a difference- if you've proven out your product in a reasonable private beta, your public numbers shouldn't be surprising. You go live, you see a big spike, then after a week your metrics go back to normal. No harm, no foul.

It sounds like they're going about it in a great way with Origami, and, once they have their numbers in good shape, if they were to launch publicly there'd be no downside. That they weren't able to eclipse their launch numbers (5k-ish downloads is normal for a standard TC launch) within a month is just a way of showing that they didn't have a grip on their growth before launching to the App Store.

As a note, there's a slew of reasons not to launch a "beta" app on the App Store- not least of which is that "New and Noteworthy" is really only for "New" apps and "Noteworthy" huge updates. You totally shoot yourself in the foot by taking yourself out of the running for the former.