We doubt these cameos were in the movie entirely for cameo sake, it’s more likely that the cameos were added in scenes that were eventually deemed unnecessary, which has led to the film simply having fewer characters in total.
It seems unlikely that the movie would need to have fewer characters for some reason.
While it seems that James Gunn wanted to do the same thing with Guardians of the Galaxy Vol. 2 and fill it with cameos, it appears, based on his comments during a live Facebook broadcast, that the final version of the film will include far fewer cameos than he had intended.