No, I would say the last 2 paragraphs show more your and to a lesser extent the authors misunderstanding of PDO, and its importance within football.
He caveats it himself, as he understands its limitations.
You suggest the only reason the best teams get a better PDO is by luck/random events. Whereas I am suggesting that the better teams in football have a better PDO because they have better players. i.e. their defenders are restricting their opponents to lower percentage shots, and the goalkeeper saves more, and their attackers create better chances and subsequently score more as a %, This is not luck, you get what you pay for.
How else is it that the top 6 teams bar us, and since Sherwood took over from AVB, all the top 7 teams have the only positive (above 100) PDO.
But no, if you want to try to explain this anomaly away with luck, rather than that we are now creating better chances, and because we are creating better chances, converting more, then go ahead with your agenda.
And in that article he presents no stats at all. Last season the top teams had the greatest PDO, but I suppose this was just luck again.
PDO in the way it has been presented here, in no way takes account the quality of the chances created, without that factored in, it basically just shows how teams are performing in 2 by themselves meaningless statistics in comparison to the rest of the League.
The only way luck will be the reason for adverse PDO's is if all teams were of exact equal strength, and created exactly the same quality of chances and had exactly the same quality of chances created against them.