Well, if you don't count Password Plus or TTTT, I only get 22 shows that fit Don's conditions. Even one of those (Act It Out) was probably local to NYC.
I'd personally never heard that 23 was the "official" number, but chances are wherever that number came from, they were probably counting at LEAST Password Plus, and they were probably counting others but NOT counting some that I located later. Professor Yes 'n' No doesn't show up in too many reference books, for example.