Yes, this has become prevalent with R&F. I suspect the addition of emergencies necessitated a change that causes AI civs to be more aggressive against CSs, thus triggering this newly added aspect of the game (they added a feature and want to show it off). Personally, I am still evaluating and trying to decide how I feel about it. While I enjoy playing the CS/envoy game and hate loosing them, I have also enjoyed the emergencies quite a bit.
Several ideas have been floated to address/mitigate this, but none of them satisfactory, in my opinion. Until we come up with a good solution, there are a couple of mods out there that strengthen CSs by giving them walls and/or additional units.