At the top of the comments, there's a button on the right side with 3 vertical dots.  Press it and you should see a Track Comments or similar.  Yeah, it's harder than it needs to be.

Login to the SA website,select the My Authors tab, then Authors Email Alerts.  Toggle the "Get Email Alerts" for each author

He's referring to the non-dismissable "This article is exclusive to PREMIUM subscribers" ad plastered on the comments section of we've read and commented on. Users, who have been conducting conversations in the comments, are now blocked from those conversations unless they're premium users.  This is an unannounced change in policy.  And, more importantly, it reduces the value in your platform and will drive away the very users SA is attempting to convert to paying, Premium customers.  Not smart.