Yes, they merely created the technology that watches everything you do. You can opt out! No worries! This certainly isn’t anything to worry about! They will definitely continue to let you opt out indefinitely. History tells me that that’s how this works.
$4/mo. for the best gmail/email app on a Mac is a no-brainer for me. It’s got some incredibly useful and time-saving features, and feels like Apple made it.
Mimestream is the best macOS client if you’re using gmail and are willing to spend money ($50/yr). There is talk of an iOS app, but nothing yet. I use mail.app on the phone.