I didn't receive any opt out. Nothing was on the install screen or anywhere else mentioning Avast. After I updated CCleaner to the newest build I had an Avast Icon on my desktop. I understand it does show up for some people but not for everyone obviously. That's a serious issue that needs to be addressed not just because of the obvious reason but also installing it can cause some major issues if a person already has active protection on their PC.
I made an account just now on these forums because it is indeed that serious of an issue. Piriform needs to fix this issue ASAP or remove Avast