probably so that if something doesn't go well, it doesn't impact as many people

The other side of that coin is that by not supporting more common uses up front, less people will have cause to try out the new functionality, which means you'll have less insight to how it's being used and less likelihood of uncovering bugs. That means when you go to build more actions on top of it, you're (potentially) building on an already shaky foundation.

Very true - also shows their lack of confidence in the feature they're deciding to roll out