They meant what they said.
Pro Wrestling Sheet reports that Cody Rhodes and the Young Bucks are self-financing their own event to be held in 2018. It would be called "All In", and would be held at an arena that would seat around 10,000 people.
It started when someone asked Dave Meltzer of the Wrestling Observer if Ring of Honor could ever sell out an arena with 10,000 people. When Meltzer said that it wasn't happening anytime soon, Cody Rhodes decided to take it on as a challenge:
Rhodes and the Young Bucks are looking to partner with Ring of Honor, the report says, but nothing has been confirmed yet.
Cody also tweeted out a photo from last weekend showing the trio, along with Marty Scurll, on a arena scouting mission:
Potential locations for the show include Chicago, London, San Francisco and Ontario, California, where the Bullet Club Invasion took place.
No official announcement just yet on the show, but things seem to be progressing towards one soon, the report says.