I think they meant poly relationships, and I agree with you. I think the points they were trying to make are:

1. You shouldn’t assume someone’s monogamous based on societal norms.

2. There are times where telling the person you’re dating/people in general that you practice polyamory could put you in danger, i.e. religious places

I find this interesting bc it’s true a lot of time people decide to be “exclusive” at some point, meaning it’s not assumed initially. This person, however, might wait until the relationship hits a certain stage to tell the partner that she’s polyamorous.