I think people are getting the "minimum points for a Blue Card" and the "minimum points to buy from DVD" mixed up.
Someone can correct me if I'm wrong, but before April 2016, if you owned any
DVC points, resale or direct, you had access to Membership Extras. There were no "minimum points for a Blue Card" at that time (I'm not even sure the Blue card even existed at that time). Membership Extras pretty much followed the deed.
This was until April 2016 when Disney decided all resale purchases from then on will not come with Membership Extras. Only direct purchasers will get it. But, there was a loophole. Once you were a resale member, your minimum add on purchase was a mere 25 points. So resale purchasers used that loophole to gain the "Blue Card." That made the "minimum points for Blue Card" at 25 points.
Until Disney got tired of that loophole in 2018 and made the minimum 75. And that started the whole she-bang... So the phrase "minimum points for a Blue Card" didn't have any meaning back during the OKW times, but it does now!