A few new things have been added to the Lijiang Tower map in Overatch. And a couple of them are probably hinting of a new moonbase map.
The biggest tell is the central pillar in the pagoda within the Garden map. Originally, the red rotating banner in the middle is that of a stylized lunar rover, and has since been replaced by a satellite blueprint mockup. The one for the Horizon Lunar Colony, meanwhile, used to feature a world map instead.
If you're one of those who avid-ly track Overwatch's lore, then yo probably might remember that there's a lunar colony in the game which is basically Winston's childhood home - the place that he grew up with, alongside his scientist father figure. Also: it's the place where intelligent apes staged a violent rebellion, kicking out all the humans and claiming the place as their own.
In addition, there were also sound leak files for the map that suggests it comes in two forms: the usual electronic whirr and buzz of high-adventure science fiction, complete with the sounds of ray guns and electric fields. But there's also a subset of sounds that are distinctly more organic, and creepier. It probably makes sense that apes would remodel their lunar home into something more befitting their physiology, after all.
As for an official confirmation, Jeff Kaplan's recent Q&A session's at least a little suggestive.
Q: MOONBASE CONFIRMED!
Jeff: Nonono I didn’t say anything! That’s a killer idea though. People are going to be very excited about the maps that we’re making. And then new gamemodes, we have some ideas…
The arcade has really opened it up. I don’t believe that many new gamemodes belong in Quickplay or Competitive. I really think you want the core of the game to feel like the core of the game, and not like a circus. I don’t think we want a bunch of gimmicks – I think you want Overwatch competitively, to have a certain vibe to it, and it should be more focused on the heroes and less focus on the gamemodes.
Now the arcade has opened the door to where we can really do a lot of fun stuff and you know, you start to see some of that, and there might even be some more cool stuff, with the Anniversary Event.