Randall's name is non-canon and was coined by a Smash player. I don't see what's wrong with coming up with our own names, so long as they're not completely random (not sure how we came to agree on Randall's, but I'm sure there had to be some sort of a sensible back-story lol)
In the game Yoshi's Story, Shy Guys often vocalized their Japanese name Heihō (not sure how that's pronounce lol). In Japanese, 'White Shy Guy' is Shiro Heihō, with Shiro presumably meaning white. "Whitey" and the like seem like they could lead to some weird racial tensions down the line, and might draw some misunderstood criticism from outside of the community. Why not go with Shiro, or some play on Shiro Heihō? Shiro even sounds like Shy. Maybe Shiro-Guy? Shiro-hō? (at the end of the day, it's all about how fun it is to say - "SHIROHO...PLEEASE SHIROH- WAIT- SHIROHO NOO" lolol) If we are gonna make actual threads for nameless characters like this, why not be smarter/more creative about the names we pick from instead of picking from random plain-sounding English names or basing it off of Randall again?