Travel blogs have no secret source of info, unless they say they've heard it officially then they're just guessing based on the information available at the moment.
Just because IB is doing something, doesn't mean BA will. Iberia's scheme is a lot more generous in earning (you can earn TP on non-flying spend and as it's based in euros you effectively get more points for spend too) so maybe they want to make redeeming less flexible on IB because they think the market in Spain will tolerate this. If IAG wanted BA and IB to be exactly the same in loyalty schemes they'd have just merged all the schemes together into one like Lufthansa or AF-KLM.