The status for a blue card is based on owning qualified points in a membership. You can have a mix of resale bought prior to 2016...when this restriction happened..resale bought after...or direct owned points at whatever minimum was required after 2016 when you bought.
If any of those contracts are then sold, and you don’t own other points that are qualified, you will no longer have the blue card,
So, if OKW contract is what qualifies you, then you must keep that if you want a blue card benefit, If you sell, the only way back is 125 direct...or more if that goes up,
In terms of having a mix of points used to be eligible for things like MM, it doesn’t matter what points you stay on...you are eligible to go. I have a white card membership...because I sold the BWV contract that made that membership eligible...and a blue card membership which holds my RIV points.
I attended MM in Jan 2020 while staying on points from my white card membership. It was noted that I had both so it was not an issue.
Of course, any new points bought resale...in addition of not being eligible for blue card...can’t be used with your other points to reserve RIV or future resorts.
So, if you want BWV, and blue card, you have to keep OKW...or buy direct points if you want to sell that.