I think we have to be careful at how we word this. I believe that such an increase could reflect a benefit. But, more importantly, it may be an indicator of greater performance on the track - not necessarily a direct contributor. Again, it is individual specific and we would have to look at the entire annual training program to make an accurate assessment.
For other sports, such as football, such an increase would definitely be welcome and could be classified as both an indicator and contributor. At least I would argue there would be a stronger case for it than for sprinting.