While it's true that Apple probably wants to reduce it reliance on Samsung for OLED panels, this has nothing to do with that. Apple get's OLED panels from Samsung for iPhones. This is a rumor about iPads and MBP's which do no use OLED panels at all.
Also if Apple went with OLED panels in iPads and MBP's, they'd most likely come from LG, not Samsung. Samsung specializes in small panels. LG specializes in larger panels. Pretty much any OLED panel for a TV (Sony for example) or monitor comes from LG. Afaik, Samsung abandoned large panel OLED manufacturing.
As you mentioned, MiniLED has a lot of the benefits of OLED without the downside of burn in. It is an acceptable stopgap until MicroLED is commercially viable at a large scale.