I think Adam2 has the explanation covered. Power outages normally don't affect the gas compressors for the big transmission companies, so unless there is a physical break in a line, the natural gas should keep flowing. So, if the gas supply wasn't adequate, it was likely due to high demand causing low pressure.

Adam2 does bring up an important point about low pressure. Many preparedness-minded folks install natural gas-powered standby generators at their homes, but higher capacity models may require higher-than-normal gas pressure to provide their rated generating capacity. I think in most power outages, the pressure should be adequate, but maybe not in all situations.

Of course, if the pressure gets low enough that even your stove doesn't work, that's pretty serious if you're depending on using your stove, a gas fireplace, or getting hot water.