I don't feel to speculate on the future results/rankings, etc. and how they might or might not have had an effect current results, that is a pointless exercise.
avast will always be trying to improve detections and continue to tweak Generic and Algorithmic detections, but it is a fine balance between being able to detect unknown malware and having an FP.
However, I echo the comments of others about I would rather deal with a possible FP than deal with an infection that wasn't detected.
avast will continue to improve and change to meet new threats, things planned for version 5.0 when combined with the Generic and Algorithmic should hopefully reduce FPs whilst still maintaining a high detection rate.