I think when it comes to "newer" releases getting represented in Smash Ultimate, I don't think it's gonna end at Super Mario Odyssey and Breath of the Wild (if we're talking about mainly the Switch era). I feel that franchises and games that were shown at the January 2017 Switch Presentation will get representation in Smash Ultimate in some shape or form whether release or post-release.
- Super Mario Odyssey: CONFIRMED as "New Donk City Hall" stage, Wedding Mario costume, music, etc.
- The Legend of Zelda ~ Breath of the Wild: CONFIRMED as "Great Plateau Tower" stage, music such as the Main Theme, Link redesign, etc.
- Snipperclips: CONFIRMED as "Noisy Notebook" song
- Splatoon 2: CONFIRMED-ish (Lil' Judd appears in Moray Towers)
- ARMS: TO BE CONFIRMED
- Xenoblade Chronicles 2: TO BE CONFIRMED
- Octopath Traveler: TO BE CONFIRMED
- Fire Emblem Warriors: TO BE CONFIRMED
- The Elder Scrolls V ~ Skyrim: TO BE CONFIRMED
- Shin Megami Tensei: TO BE CONFIRMED
- No More Heroes: TO BE CONFIRMED
In regards to NMH, SMT, and Skyrim, it could happen, though I will be surprised if they don't even appear in trophy form. Fire Emblem Warriors and Octopath Traveler I feel could be very good candidates for good song selection. Releases like Splatoon 2, ARMS and Xenoblade 2, though, I feel will be in no matter what, whether it be characters, music, etc.