We recently explored what it would take to support IP address validation - cost to implement, risks, and value to subscribers. We decided that it doesn't make sense to prioritize the work over other important projects any time soon so we removed it from our roadmap.
I know there are some people out there that want this and this is a disappointing decision. The feature is not entirely off of our radar, we may revisit it in the future, but since we aren't actually planning to do it soon we thought it best not to communicate about it as an upcoming feature any more.