I don't think so, sadly. Labour want all those right-leaning votes. This nation has historically voted with a lean to the right in 90% of elections so it is a sound tactic. Right leaners all hate Diane Abbot (wonder why?). The people who support Diane Abbot are all desperate to get rid of the Tories anyway.
A no lose tactic here. Except loss of integrity - but Starmer doesn't have much of that anyway.
If you're implying that people don't like Abbott because of her colour with the "wonder why", I think that's a bit of a cheap shot mate, and wildly incorrect.