AMD took to a launch even in South Korea with revealing their new hardware in mind, but they might have revealed something more during the showcase. In a video for AMD's new GPU, the RX Vega, some Halo 3 artwork was shown off.
You can see the Halo 3 artwork mixed in with other games in the video below (via Segment Next):
Now, it's being thought that this might mean that Halo 3 Anniversary could be seeing a PC release, however, it could also mean that the Master Chief Collection is getting ported to PC. The Master Chief Collection consists of Halo: Combat Evolved Anniversary, Halo 2, Halo 3, and Halo 4 and has been rumored for PC for a while, so seeing AMD use Halo 3 art could apply to both games.
In 2015 we saw a rumor for Halo: The Master Chief Collection and Sunset Overdrive would be heading to PC in the future. A year later, in 2016, the rumor surfaced again. Of course, if the game does come to PC it will be via Windows 10, supporting the Play Anywhere feature.