No, they’re talking about Roundup, specifically glyphosate. The GM plants are incidental.
I've heard plenty of conservatives mock the greenies who've been warning about the dangers of “Frankenfoods”, but food that is meant to withstand pesticide can have very serious consequences for those who consume it. I would assume it could be particularly dangerous for pregnant women. Just try to avoid foods made with GM soy, corn or beet sugar...it's next to impossible.