NTSC was designed to be backward compatible with the B&W broadcasts that came before. From the wiki article Another Scott linked to:

The committee in March 1941 issued a technical standard for black and white television.
...
In March 1953 it unanimously approved what is now called simply the NTSC color television standard, later defined as RS-170a. The updated standard retained full backwards compatibility with older black and white television sets.

So anything broadcast in 69 can be displayed by a TV built after March 1941 thru anything built today as HDTVs include an NTSC tuner.

That said, I have noticed my HDTV is a bit less forgiving of out-of-spec signals. I tried my Atari 2600 on my set and most games came out in black & white as the way it generates the color signal isn't exactly right. Also a portion of the games had a scrambled signal, most likely caused by the games sending too many or too few scan lines. This is possibly because the sync signals(and thus scan line count) are totally controlled by the game code. I doubt the scan line count would be an issue with a broadcast from 69, though the the way it recorded color may have issues like the 2600.

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