HI Piyush,
if you parse the app access log, you will see entry below and you have session appened at the end and you could join with CMN_SESSION table to get the number of unique session and user_id from the table and those are the number of people logged into the new UX.
10.***.xx.xx |[08/Oct/2018:04:06:39 -0400]|GET /ppm/rest/v1/private/unreadPushNotificationsCount?_cb=1538986048971 HTTP/1.1|200|105|78|5262043__DF518DBE-1D23-40F9-AB3B-88B4660C0A2A
Tomcat Analyze Job will populate the data for you in the *Log Tables and you can build a portlet too.
Regards
Suman Pramanik