Every gas meter I've ever had has been purely mechanical. Have you ever seen one that needed mains electricity to work, and that acted like a shutoff valve when it lost it?
Many rural houses have tanks on site because there are no public gas lines to connect to. My house has a 1000 gallon tank and is not vulnerable to the above, for example.
eg: https://en.wikipedia.org/wiki/Natural_gas_storage#Pipeline_c...
There may be more than a day of capacity just in the pipe network.