“Activity” page does the same thing.
Earlier you had only a small box for Recent comments. Now you have a complete page dedicated to same thing.
Also, on the activity page, there is one dropdown on the right hand side which is set by default to
“show : Everything”
You can use that and set to “Replies” to check out only replies under forum topics.
If you want to check out comments below any pots. you can set it to “Comments”
Do not forget to set it back to “Everything” else you will miss out on the lastest updates.
Please bear in mind that like earlier, even now the comments under any posts are moderated and will be posted only after admin approval and hence wont appear immediately. But the chats in forums and groups does not require approval.
Hope that helps. Do let me know in case of any other concerns regarding functionality.