This would allow a quick and easy way to update your blocking lists, rather than having to log on to your computer and open the web page, and then navigate to your call log to add the recent call to your block list.
Often, I answer my calls with the mobile app, and when there's a telemarketer calling, I would like to quickly add the number to my blocked list. I use the mobile app to answer calls to my home when I am away from home and my computer. It's difficult to remember to log on to my computer when I get home to add the blocked number. They just keep calling back again, until I get to it.
Anyway, yes, I'd like to see this feature added.