"Scan" means they take the data out of the "email" silo and use it for purposes other than providing email services to the user (such as using it for advertising).
Searching is not "scanning". Nor is any other normal behavior of providing email services.
So the question at this point is does Google keep your email data silo'd or do they use it for other purposes?
That’s only a dream. Google also scans email snd combines the data with that of all the other users for spam filtering purposes, which is a big part of ‘email’.
It’s not difficult to put together creepy functionality and twist it so one of the purposes is providing email service.
Don't be pedantic. Defining "scanning" as "anything that looks at the bits on disk" makes the word meaningless in this context, because then yes, Google must absolutely "scan" it to provide basic functionality, and heck every service everywhere must "scan" their data to provide basic functionality. But that's not useful to talk about.
No idea, I don't use Google Now. I hope so, but it wouldn't surprise me if Google "forgot" about that step. But at least that's for the benefit of the user.
According to my understanding of Google's privacy policy, your account data is essentially global by default, they don't need to explicitly ask you service by service where they can use it. IANAL, though.
Searching is not "scanning". Nor is any other normal behavior of providing email services.
So the question at this point is does Google keep your email data silo'd or do they use it for other purposes?