That's a false equivalency.
Was he undefeated because his made up philosophy made him undefeatable? Or was he simply the best pure martial artist, and his made up philosophy was actually irrelevant?
You're describing Dumbo with his feather. Is the feather actually magic and makes him fly? Or can he fly regardless and he simply believes the feather is magic?
It's just marketing. It's giving Goku a new form they can sell figurines of.
After all, Instant Transmission is an amazing new power for Goku, but they can't sell merchandise of Instant Transmission. Not like they can sell Vegito or SSJ3 merchandise.