I honestly don't remember a promise of no commercials from Cable, only certain channels one could receive from cable.
That's because cable companies could not promise "no commercials" for any channel EVER*. Cable began as a way of retransmitting broadcast stations to people who could not put up their own antennas (CATV is "community antenna TV"), and broadcast stations have ALWAYS had ads.
It wasn't until cable had enough market saturation and satellite services matured to the point that satellite-delivered content networks like HBO became available, and it was HBO's promise of "no ads", not the cable TV company.
* with the exception of the PEG channels or other local origination services. Otherwise, cable is retransmission of other people's content, and those other people decide if there are ads or not.