If they release in the next 20 hours, it'll still be less than 3 weeks…
Planet are a very small company, and I'm inclined to cut them a little slack. The Gemini itself was a few months later than we hoped, but it did arrive, and with pretty much the hoped-for spec (slightly better in some ways, not quite as good in others). From the vantage point of a year later, that delay isn't important; the device itself is. I gather that people who've had to contact them directly about e.g. broken machines have mostly been happy with the ultimate results. They promised a way to flash various operating systems, and they did so. (It may not be as easy to use as we'd like, but it's probably a darn sight better support than for most Android phones.) And so on.
As far as I can tell, Planet have been working in good faith all along, and so I'm happy to forgive them a little optimism on timescales.
By the way: does anyone know what the effects of upgrading from Android 7.1.1 to 8.1 might be? Will any of my apps stop working? Will I have to set up all my settings again, or my launcher, &c? Will it still be rooted? And are there any new features to look forward to?