Original 4chan/Instagram post - Instagram was quickly deleted. Note the empty battlefield artwork.
Few notes:
1. Empty battlefield artwork has not been released as far as I am concerned.
2. This would then line up with the Corocoro leak of 108 stages if Geno, Isaac, B&K, Mach Rider, and Chorus Kids all bring a stage.
3. Considerable movement for existing fighters on the panorama artwork was done. Among them:
- Mii Fighters were moved for Shadow and grouped together above K. Rool.
- Mii Gunner was moved entirely to make Banjo room.
- Olimar was shifted to Snake's left to make room for Isaac.
- Space for Ken already exists.
- Luigi was moved and replaced by the Mii Fighter trio. Luigi was shifted to be above Bowser.
- Marth was shifted to the up + right AND had his stance change to accommodate Mach Rider.
- Geno space already exists above Ness and below Dark Samus.
- Pokemon Trainer was shifted right and Jigglypuff was moved closer to Geno to make room for Chorus Kids.
4. Sakurai had the big deal about
buying something that looks a LOT like Mach Rider to use as a "reference point" for his current work.
Really the only downside is Rex/Pyra or Malos additions. Could be reserved for DLC because to me they're the most likely 1st party early additions to sell a DLC set on their own.
It may truly be happening. Best timeline.