Umm...No. Even if we assume that MLB was fully integrated by 1950 (which it certainly was not), here are Ted Williams Stats:
1939-1949:
8 Seasons Played (1,184 Games)
314 Doubles (Led the League twice)
56 Triples
265 Home Runs (Led the League four times)
1,038 RBIs (Led the League four times)
1,082 Runs (Led the League six times)
1,488 Hits
Won 2 MVPs and placed in the Top 3 4 additional times.
1950-1960:
11 Seasons Played (1,108 Games)
211 Doubles
15 Triples
256 Home Runs
801 RBIs
716 Runs
1,166 Hits
Did not lead the league in any of the above-categories.
0 MVPs and placed in the Top 3 once.
Small sample size, I agree, but Ted Williams' numbers definitely tailed off after integration.