It was an alternate reality. Franklin never went to college. He went to an elite prep high school. The alternate reality was showing what may have unfolded if Franklin had done something different. Still a struggle, just a different type of struggle.
Yeah, he went to an elite HS in The Valley, that's how he knew his white friend Rob. The college he went to was also almost all white & he didn't adjust well. He told Mel in Season 1 he didn't wanna go across the country to an HBCU and be so far away from his mom and family.