The whole idea of it being an integral part of avast is so that it is for avast community, so I would say that isn't their intention or they would have made it available as a standalone add-on.
In its current state the add-on can't be updated outside of avast, see image, in firefox, there are no Options or Remove button and no Find updates, etc (I guess this would be the same in Chrome). Any update to the webrep is done through avast.
When other functionality is added to it, such as info from the virus labs, etc. that too may only be available for those with avast installed. So in isolation I don't believe it will bring much and rather than promote avast could do the opposite.
