No, they were recording data from every user in any browser that accessed google.com and their other sites. That behavior is normal for the majority of sites o

No, they were recording data from every user in any browser that accessed google.com and their other sites. That behavior is normal for the majority of sites on the internet. AFAICT, reading the article, Google is going to stop collecting data from all browsers/machines that connect to their websites and only collect data from browsers/machines that are logged in to a google account. Further, they are deleting data saved from browser/machines that were not logged in. Users that were using incognito-mode are a subset of all users that use their sites that are not logged in. In general, a website can not distinguish between a user in incognito-mode and a user not logged in except in that, a user not logged in but using a non-incognito mode would have manually clear their cache, cookies, local storage, etc where as in incognito-mode that is done automatically when you close the last tab.