[pmlnr]

This is true, I'm well aware of this, but at least there's still a choice.

Unfortunately nothing is truly stopping Google to pull a Slack move and close the gateways... unless the amount of IMAP/SMTP users are significantly higher, than we know, or that those users are tech influencers Google don't dare to loose.

[erichurkman]

I would wager that G Suite users will keep IMAP/SMTP alive via Outlook and other enterprise deployments.