The games are listed in the list of represented franchises, that much is true, but they have no content in the game. No spirits or songs or anything else.
I ran an international trademark lookup on Star Twins and Blast Dozer, the Japanese titles for Jet Force Gemini and Blast Corps, and I did manage to find evidence Nintendo might still own the trademark for Star Twins in Japan, though I couldn't find any evidence for Blast Dozer.
I do think there is credence to the theory that Nintendo might have, at one point, assumed they owned the IPs before realizing that they don't.