They are also wording their defense very carefully:

"[people claim] YogaGlo will now try to shut down any business or individual teacher that films a yoga class, which again is not true. There are many ways to film a class as evidenced by the many videos that currently exist that do not violate our patent."

Note how the overall tone here is "it's incorrect to suggest we're going to shut down all yoga class filming," (incidentally, a suggestion nobody is making) and the subtext is "so long as you film in a way that doesn't violate our patents."

edit: This post of theirs really seems to just dig them in deeper. They look like clueless assholes.

That is the point of the patent, isn't it? They have the patent so that no one else can use the same filming style. They don't intend to sue anyone, but if someone is filming in ways that are too similar to theirs, they will try to get them to stop. That can range from polite emails to cease-and-desists.

So basically, they don't intend to sue anyone over the patent unless they can? How exactly would you sue people who stop the infringing behavior upon request?

They're already sent cease and desist papers out, which is a pre-cursor to suing.