I believe it is sarcasm, but with the death of E3 anything is possible.
That said, I’d say it is more likely to see Nintendo announce it at the Tokyo Game Show instead. (This would put it at late September, which is right around when the Switch was revealed back in 2016.)
They need to chill on releasing new generation consoles for a while (All of them, not just Nintendo). Give the current generation time for the game devs to fully utilize them. This constant upgrade in hardware for consoles is getting rather tired.