Yes, he didn't directly say that he was discrediting Gen II for all it did (and that is a poor choice of words on my part). However he did say that the features they did introduce could've been introduced later (which in and of itself is a poor argument since we don't know if they would've introduce those features without Gen II in that hypothetical scenario and the same argument can be applied to other generations). Also, in the post, he called the previous poster's argument "silly" when they stated that the features Gen II introduced were important to current gameplay and then said the already mentioned comment. So while he may not have been discrediting that generation for its additions necessarily, he was in a way deflecting the praise away from Gen II because they "could've been introduced later."
I believe he was just simply saying that, had gen 2 not existed like pokemonfreak97 proposed, that its additions would eventually be realized in later games. That's it. No negative connotations associated with it.
Ok, except that's an argument based completely on hypotheticals, we don't know what would've happened if Gen II didn't come around. Yes, the additions could've taken place, or maybe the series could've died off leaving Digimon/Monster Rancher/Yu-Gi-Oh/whatever to replace it or it could've went on to become a Shin Megami Tensei ripoff. Extreme examples I know, but we can't say that it couldn't have happened. What we know for sure is that Gen 2 occurred and gave us those additions, so I completely agree with Pokemonfreak97, we do owe Gen 2 for introducing those additions because they became important staples that the games still use today.