Nobody in the US knew about Dragonball Z in 1992. We were barely getting a few random dubbed episodes of the ORIGINAL Dragonball around that time.

On top of that Super Sonic was not common knowledge among gamers back then either. I remember my cousin telling me about the "rumor" that Sonic turns into some super powerful gold version and it just sounded like one of the many other such fake secrets back then.

Very few people in the US would have known about both Super Sonic and DBZ back then, much less also know about Super Saiyan Goku.