There are a few you missed on your list. The full match list is:
- Macho Man Randy Savage vs. Jake "The Snake" Roberts
- Rikishi vs. The Rock
- Alundra Blayze vs. Paige
- Larry Zbyszko and Arn Anderson vs. Ricky "The Dragon" Steamboat and Dustin Rhodes
- Tatsumi Fujinami vs. Ric Flair
- The Bushwhackers (Butch Miller and Luke Williams) vs. The Natural Disasters (Typhoon and Earthquake)
- The Outsiders (Kevin Nash and Scott Hall) vs. Harlem Heat (Booker T and Stevie Ray)
Aside from Alundra Blayze vs. Paige, all of these matches actually happened:
- Macho Man Randy Savage vs. Jake "The Snake" Roberts: This Tuesday in Texas (1991)
- Rikishi vs. The Rock: Survivor Series '00
- Larry Zbyszko and Arn Anderson vs. Ricky "The Dragon" Steamboat and Dustin Rhodes: Clash of The Champions XXVII (1991)
- Tatsumi Fujinami vs. Ric Flair: Superbrawl I (1991)
- The Bushwhackers (Butch Miller and Luke Williams) vs. The Natural Disasters (Typhoon and Earthquake): Summerslam '91
- The Outsiders (Kevin Nash and Scott Hall) vs. Harlem Heat (Booker T and Stevie Ray): Halloween Havoc '96
Since this is specifically a Showcase rather than a generic DLC pack like the Legends pack coming out on Tuesday, I would assume that we'll get new attires/builds for all of the wrestlers involved as well as the arenas listed, which would certainly include a retro Ric Flair, all usable in other modes.
The Alundra Blayze vs. Paige match makes me raise an eyebrow, and I've heard discussion that this was possibly included because they couldn't/wouldn't license Bull Nakano or Luna Vachon and inserted Paige into the match instead. (Similar licensing issues likely kept Owen Hart out of the game as well, given evidence suggesting that he was originally meant for inclusion.) The question is whether this match will take place at an arena where an Alundra Blayze vs. Bull Nakano or Alundra Blayze vs. Luna Vachon match occurred (for example, Summerslam '94) or if it will be dumped into one of the arenas already in the game.