That could just mean they're not gonna sell it again for a couple of years, lol. I'd be more hyped if they said "Last chance before flyable, in Alpha 3.18"
According to the Roadmap, work is supposed to finish up on the Hull C in late February - I'd guess that CIG had planned for it to be in the "3.18.x"\"3.19" release, but (as much as I hate saying this) with the number of bugs still in the PTU, it may still end up in 3.18.
Either way, if you can trust CIG, they intend to have it out at\before IAE this year, as baring a MISC (or transport) ship sale, that would be the next time it would normally be expected to go on sale.
I'd actually been expecting it to come with Pyro, but as the ship is apparently scheduled to arrive this year (at or before IAE), having it arrive when the SRV does (work scheduled to finish late February as well) is likely. The release would also require ship tractor beams to be working (Work scheduled to finish late June) to provide a way to have the Hull loaded\unloaded - It won't fit in a hangar or be able to land when loaded, so CIG would likely want a way to load\unload the 32SCU containers onto it that doesn't require them magically appearing.
It will be interesting to see how the rest stops\stations handle the number of Hull C's, as well - They can only use these when loaded and can't land in the hangars/pads with cargo attached, so will be reliant on there being enough docking points to allow players to access them (or will be left floating free while crew EVA to visit station).