Anonymous call rejection feature

I recieved an email today 2/19/2020 from xfiniity/comcast stating "great news, changes are coming to your xfinity voice service".  After experiencing so many negative changes in TV programming, billing and customer service. Whenever I see a "great news" from xfinity/comcast red flags immediately come to mind because it is usually not a good thing for us the customers.

This is the first time I have even checked phone forum posts thinking how many issuses can there be with the phone, gosh my ignorance in reading SO many issues customers are having just like with the rest of comcast/xfinity services.

I have a triple play package with voice land line sevice and in the email it states how to activate the anonymous call rejection feature, I also looked at voice services and see there is a call screening feature that can be activated. 

My question, is there a charge to activate one or both of these features now or in future billing as possibly a "voice service supplemental fee" or some such name. Also, if activating either of these features does this change/alter my existing contract in any way?