Wave Race is a franchise that is just there. The games do have their decent share of fans but that may not have been enough for the franchise to stay afloat(first and only pun, I promise). The original Wave Race was released in 1992 for the Game Boy and would later be released for the Nintendo 64, as one of the launch titles, in 1996. Wave Race 64 was praised for giving players a somewhat realistic sense of watercraft racing and its 4-player mode.
A sequel to Wave Race 64, titled Wave Race: Blue Storm was released for the Game Cube in 2001, once again getting praise for successfully emulating the feel of riding a jet ski, water physics,and its gorgeous graphics. The Wave Race franchise has, sadly, been on a hiatus ever since until just recently.
According to sources, Nintendo producer and developer Shinya Takahashi entertained the possibility of a new Wave Race being developed at one point. During the 14th BAFTA Games Award he was quoted saying "You may see the game again" in regards to Wave Race. "We have been trying to make many games, so that may be one of them… And I personally love Wave Race."
Takahashi was the director of Wave Race 64 and would supervise Wave Race: Blue Storm as the Project Lead for the game, so it is possible that he may be either working on a new title, or that Nintendo are planning on re-releasing either of the games on the virtual console, which wouldn't necessarily mean it's a new game but that could lead to something bigger.
Until then, fans of the franchise can choose to listen to Takahashi's words and keep hoping for a new Wave Race game hitting shelves, but they probably shouldn't hold their breath.