Spigot has the possibility to work on the snapshots, but they choose to not publish their work until after the update. That is why Spigot is available so quickly. We however have to wait until after Spigot decides to make push their changes, and only then can we start working.
We've been working...
There Is No ETA
Updates to Paper do not have any sort of estimate for when they release, ever. Any and all updates will arrive when they are ready, and the only thing to do is wait for them patiently along with everyone else. Join our Discord for more updates on the progress