Bliz needs to put some type of tracker so you can follow any posts you have made. I know EvE online has this. I made a post a few days ago and can’t find it to see what or if any feedback was provided.
This feature does already exist. You’ll receive a notification for any interaction on a topic you created by default, also you can set the notification for any topic by clicking on the little bell icon near the bookmark button.
To find all of your activity you can click on the button below your name on the upper right (near the sarch box) and then click on your name inside the notification box. From there you can use the left side navigation to find all your topics and posts.
Hope it helps.