If web sites are starting to track me via first-party cookies (which I allow for now) those will be banned aggressively as well. Currently I am somewhat lax on deleting them on browser close (I like to stay logged in for some sites). But this will change on a whim when this becomes mainstream.
Check out the Cookie AutoDelete addon – it can be configured to keep cookies from select, whitelisted domains, and delete everything else every time you close a tab. You can have the cake and eat it too :)
I block all third-party cookies, accept all first-party cookies but delete them when Firefox closes except for few sites I'd like to keep being logged in. Those I approve in the "Manage Permissions" section of Firefox. There are plugins for this but this is a Firefox native way of doing it.
I'm always more certain that we're going to see ad based web sites rendering with webassembly in a full page canvas. Some sites will implement ways to let us copy and paste text, others won't.
Heck, companies are already starting to use CNAME records to fool ad/content blockers. I don't think what you're describing is far from becoming reality.
