a trigram that I don't think has an established unique technical meaning

For what it's worth, that's my impression too. So I take it Eli is coining his own term; I don't see anything wrong with that.

I suppose the thing I'm objecting to the most is the absence of 'sampling'

I take it you mean that you'd like the 3-word description to include "sampling", rather than that the 3-word description implies sampling that isn't being done (which is how I first misinterpreted your comment!). I agree that a description with the word "sampling" in might have been more informative -- but probably necessarily longer too.

they aren't "probabilistic constraints" in that the constraints are satisfied with some probability

I was parsing the phrase as (probabilistic (constraint methods)) rather than ((probabilistic constraint) methods) and therefore wasn't expecting to see the constraints being satisfied only with some probability.

Anyway: It's possible that Eli didn't choose the best possible 3-word description for the class of methods he had in mind. But that seems a quite different complaint than that the paper doesn't embody the term as Eli meant it.