Re:Chrome 68 Released: HTTP Sites Marked as “Not Secure”
by nsgi on Thursday July 26, 2018 @02:38PM
(#17619763)
It's more likely that Google's support for HTTPS everywhere caused them to do both. It introduced HTTPS as a ranking signal in 2014, well before Let's Encrypt.
I think that's what made Google push this, since they are on the board of advisors for the Let's encrypt certificate authority.