No this is a common failure. The TS switch can fail and the signals still work but not brake lights. In the 70/ and later cars, this is commonly caused by the integrated hazard switch
Check the "output" of the brake light switch. I believe this is the white at the column TS switch connector. If you have brake light power there, of course pedal depressed, then it's the TS switch
Try working the hazard switch a few times