@s390g2 Thanks for the response. I have already activated the EasyPrivacy filter list but didn't really know what it was until now. I'm not sure I believe this filter list removes all trackers as it claims but then again we've no real way of proving that with extensions either. The plus for Disconnect is that I can toggle content blockers on and off (some are vital for page functionality). Opera's EasyPrivacy is just a simple on or off.
I do understand permissions are necessary for extensions to be able to function. It makes sense a tracker blocker would need to access my browsing data. It's unfortunate that extensions are extremely vague as to what these permissions are doing for a specific extension. I assume Disconnect is just monitoring browsing data to search for trackers. No way of really knowing though.