I am sure it has zero impact in practice, but theoretically, there’s a random component that isn’t part of the initial conditions.

Our current understanding of radioactive decay is that it is 100% random, and that the law of conservation of momentum also holds at quantum scale. If so, radio-active decay that emits a particle that escapes from an orbit around the meteor (relatively easy, given the lack of atmosphere and low mass of the meteor) has a (minute) random effect on the velocity vector of the remaining larger part.

Because individual decay events are uncorrelated, adding up all the effects of radio-active decay over time will make the already extremely tiny effect a lot smaller (by the square root of the number of decays, if I’m not mistaken, but there may the timing of decays gives earlier decays a larger effect on the eventual course, so it may be slightly less dramatic).

That’s why I doubt it has any practical impact.