There were three Mario Party games launched for Nintendo 64, three for GameCube and three for Wii. Then this suddenly stopped. There was only one game made for Wii U (Mario Party 10), and so far we've only got one game in the series for Switch, which is Super Mario Party from 2018.
This isn't because the series isn't selling anymore, quite the opposite, as Super Mario Party has sold more than 12 million copies, but despite this, there hasn't been any talk about a sequel. But now ComicBook.com has noted something interesting. The image below is the digital pamphlet the Mario Party developer NDcube is using to recruit staff for their next game, and it really seems to imply that they are preparing a new party adventure with Mario.
So far, nothing is confirmed, but at least it seems like there are good chances that we'll get more Mario Party in the not too distant future.