The article mentions they use DNA testing to determine the sex and also that it's tough to find usable DNA samples. Could it be possible that male fossils are more likely to have usable DNA and thus bias the results?
You can't change the hypothesis to match data. We try to avoid doing that in science ;)
On Land of the Lost "Grumpy" was called he and "Alice" was called she, but I don't think anyone knew their sex for sure. "Alice" was an Allosaurus.
Well, the dinosaurs that are alive today do, at least. For other dinosaurs, we've only fairly recently realized we have soft tissue and maybe DNA in lots of fossils. So, maybe, but we don't know yet.