Clicking links doesn't sound like the sort of thing that email servers would know about one way or the other. Likewise for engaging (or not) with emails at all. What setup do you have in mind where this is the case?
Given that AFAIK Apple Mail downloads entire messages regardless of whether they're opened, Apple's change here doesn't seem likely to affect delivery rates in this way anyway.
Your IMAP server doesn't report read status back to the sender. Unless your e-mail provider is an advertiser *cough* Google *cough* the advertiser doesn't know if you read a message just because the IMAP server marked it as read.
Also an IMAP server's read status doesn't mean someone manually interacted with an e-mail. If you mark messages as read in bulk, even if the provider reported that status to an advertiser, says nothing about engagement.
You can request a read receipt with emails, which will cause the MUA to send an email saying you've read the message (although I suspect most clients default to asking you if you want to send it before doing so).
Given that AFAIK Apple Mail downloads entire messages regardless of whether they're opened, Apple's change here doesn't seem likely to affect delivery rates in this way anyway.