I think you're thinking of what happened to UC Berkeley, but I'm not sure this is true of "most" lectures.
After all, many lectures already have subtitles, some lectures were produced outside the U.S. or not produced with Federal funding, some lectures were produced by institutions that may disagree with the interpretation of the law advanced in the Berkeley case, some lectures were produced by institutions that may not have been targeted with such claims, and some lectures are hosted by entities other than the institutions that produced them.
They definitely still do have videos. I use OCW quite a bit. Producing the videos, formatting, distributing, and hosting them is more expensive then going without them so sometimes they go without them.