Just curious because it's been a good while since the last, and Fish did say it's gonna take a long time... But maybe he could be involved with developing something absolutely game-changing?

Who knows? This is a longer wait than usual, for sure, but that might just be because things came up in Fish's personal life. I think we'd all be stoked to have a big update, but without any confirmation (or teasers) from the man himself  we'll just have to wait and see what's in store. There are plenty of big, heavily requested features that would take a mountain of work to develop (multiplayer, a fight against Swirly D, an oversized spoon weapon), but as of now there's no telling what the update will actually be about.

That said, I know that occasionally Fish releases pre-release information for each update on the Discord. Perhaps he's said something enlightening on there.