I'm not so sure associate people with primates is problematic in general.I don't think that people think that Goh is black because of his English dub voice actor. Plenty of characters have voice actors that don't match their ethnicity, especially in anime, and I've never heard of people thinking that Goh was black either. Plus, associating people with primates in general can be problematic. In the U.S. at least, there is a clearer association with African Americans and primates due to racist imagery/insults, but that isn't really an exclusive problem for just the African American community.
With all that being said, the dream sequence was rather short and didn't really do much other than to Goh finding Grookey on his arm. Unless they actually are going to have Goh become a big brother, which would be kind of cute, then the dream sequence isn't really necessary and the dub could easily edit it out without causing much of a problem.
I mean, if you have white characters associated with primates you won't have problems.
In the same way, I doubt a Japanese character associated with primates by Japanese writers in Japan would be a big issue.
The big problem is because Go has darker skin, so people on other countries will assume he is black. Then, the issue to associate him with primates will start.