Much as I'm a fan of losing the referrer data from a privacy point of view, I'm suspicious of the timing.
Previous G changes that made this happen have been passed off as mistakes but once the big shift to using user behaviour to rank sites starts happening it gets rolled out?
1. Only Google being able to provide some data on searches that led to your site
2. leads to more sites running GA
3. leads to more user behaviour data for Google and less for their competitors
4. leads to better SERPs at Google (if used properly)
5. leads to more searches on Google.
leads to both
6.1 more user data for G and less for competitors (go to step 4)
6.2 more G only referrer data (go to step 1, go directly to step 1, do not pass Go, do not collect $200)
Similarly, if they can collect the user session via adsense - cookies, super-cookies, browser and request footprints - heck they already know you clicked on a link to go to the site after all?
7.1 more user behaviour data for Google and less for their competitors (go to step 4)
7.2 leads to better targeted ads from G, less well targeted from competition.
7.3 leads to more sites using adsense
7.4 leads to more user data for G and less for competitors (sound familiar? go to step 4)
Whether G now actively campaigns on user privacy and the referrer, or is content to sit back and let others do so, the more users who act on privacy concerns the more G ends up as the only one with the data.
Looks like a boil-a-frog method of lock-in to me.