He's basing his thoughts on a study that has been floating around, and posts by at least one member that had bloodwork done post Oxandrolone only cycle. Both sources of information clearly showed Ox as being suppresive.
I'm not going to search for these theads, but they're here I've seen them.
Yes it was "thought" and people have "heard", but I've yet to see a shred of evidence that says Ox isn't suppresive. And just because someone does an Ox only cycle with no PCT doesn't mean it was the right thing to do. Hell, ten years ago I did a Deca only cycle with no PCT and kept some gains.