so it is a side effect, obviously an unwanted side-effect.
It seems pretty obvious to me from the wording in that post that this is a desired side effect (note that "too" at the end there). Especially when you consider that this side effect was pointed out by the same person announcing the change, at the same time as the change was announced, without any mention of plans to avoid the side effect. (And honestly, if they wanted to avoid the extra oversupply cost, it would have been a very quick fix.)
Agreed, I also understood from that post that they actually wanted to make oversupplying more expensive to prevent spamming. I love it anyway, you can still have themed companies, but spamming is (almost) impossible.