According to leaker Zippo, two of these games are classic GameCube titles in the form of F-Zero GX and Paper Mario: The Thousand-Year Door. This isn’t the first time that HD remasters of Paper Mario: The Thousand-Year Door or F-Zero GX have been rumored, but Zippo believes that both will be released by the end of the year.
And the plot thickens why Dolphin was recently removed from Steam…
We know why Dolphin wasn’t put on Steam.
Valve continues to host RetroArch and the various cores, so it’s not like they’re opposed to emulation in general. The ability to copyright “magic numbers” in the US (Valve is an American company) isn’t up for debate, and it would also put them in violation of the DMCA, so it’s not hard to see why Valve would be worried about this specific emulator.
As for Dolphin, they have options: