I suspect this is the case here as well. Mark has never been quite accurate when it comes to hardware leaks, compared to Ming. My guess is all these are intentional from Apple, for a few reasons.

OLED is expensive. I think Apple has learned its lesson with NAND, ( Where its projected NAND and SSD market cost does not align with reality ), Sharp does not yet have an OLED that is competitive, they are focusing on a different type of OLED technology that is much cheaper to manufacture, Ink Jet Print style OLED, one of the original promise of OLED was being even cheaper then LCD. But its quality is not on par with Samsung. Credit where Credit's due Samsung make amazing progress with AMOLED technology, if you think in the few years time what they have manage to achieve is uncanny. S9 now has the best possible display compared to even professional monitors. The only possible improvement left are brightness, power, price and longevity. Apart from Price, the other three will likely see improvement in Note 9, and more so in next iPhone. Samsung has been able to improve its OLED technology with every iteration twice or somecase three times every year.

Apple is paying up to $100 a pc to Samsung for every OLED display. And if you include NAND & DRAM, which is extremely profitable in the last 2 years that is why people joke Samsung make more money selling components to Apple then selling its phone. While not entirely correct it is certainly not baseless. One reason why Apple will never move back to Samsung Fabs is to avoid putting too much egg in one basket. Despite the consistent rumours, which I guess is another play for TSMC to lower their price.

Apple has literally NO other choice in OLED the market. As much as LG and BOE wants the business from Apple, both do not (yet) have the technology and capacity to output something similar to Samsung. Certainly not in this year's iPhone. I once written off BOE being far too early in the game, but it turns out BOE isn't far off, and are making much better progress. Compared to LG which I have no idea what they are doing in terms of Mobile Display. They seems to have difficulty getting it right, meanwhile their own WOLED display are much better. That is why I think the rumoured Apple investment in LG Display plant might have more to do with bigger WOLED screens then Smart Display.

I think the larger 6.x" iPhone X Plus is pretty much guarantee this year. That display panel is going to be even more expensive.

My problem with MicroLED is that it is still very much a fantasy, at least in terms of high PPI, mobile display panels. The MicroLED shown by Samsung "Wall" and Sony are completely different thing. When people talk about Mass-Transfer being the biggest obstacle, I have yet to see a single 600ppi+ MicroLED display that have said to solve their ultra low power passing through each and every pixel, being energy efficient as advertise, and brighter then LCD. ( Do Correct me If I am wrong ) Once they solve that, or at least being good enough to compared to OLED, they will have to solve Mass-transfer as well. Or using possibly other innovative method to mass manufacture.

I wrote in 2015 MicroLED isn't going to happen as rumoured at the time for 2017, I wrote even 2018 is a bit of stretch given the best case scenario possible, and now as we stand my guess is that even 2020 seems unlikely. ( And I got Attacked by Apple Fans every time i said that, no wonder why some groups of people hate Apple's cult so much )

The good news is Apple is back on track again spending big in R&D. [1] So I hope I am wrong this time around.

[1] https://www.aboveavalon.com/notes/2018/3/15/an-apple-rd-bona...