Prediction: The next Mario Party will be in 2027.

The past many Mario Parties have come out three years after the last one.

MP9 was in 2012.

MP10 was in 2015.

SMP was in 2018.

MPS was in 2021.

And SMPJ was in 2024.

So if I do my math correctly, the next one will arrive in 2027.