If by some chance you don’t own Quake games yet, you can by them if you want. GOG sale is live already, Steam will probably appear at some point soon.
There is a rumor Quake2 may have a remake similar to Quake1 and that it will be announced during Quakecon, so might be a good idea to own Quake2 on Steam in case they give it for free.
Kind of odd that Quake2 on Steam is not on sale. There are also some avatar you can claim on August 10th: https://store.steampowered.com/news/group/33028765/view/3687932599975160360
Notice one of them is Quake2.