Samsung essentially doesn't even make AMOLED displays larger than ~9" with PenTile. The Galaxy Tab S-series has always used Full RGB OLED on the highest model, including the original Galaxy Tab S 10.5" from 2014 all the way to the Galaxy Tab S7+ 12.4" (120Hz) in 2020.LOL. Mini-LED is just marketing for FALD with more zones, but it is still an LCD display. I would generally take an OLED over any LCD technology, but now I wonder. Will the iPad Air use LG's RGB OLED technology, which is essentially red, blue and green filters (like in an LCD) back-lit by red, blue and green OLEDs (which, combined, produce white backlighting), or is it going to be using Samsung's Super-AMOLED tech, which we have in iPhones and which relies on a less sharp pentile arrangement? I can see how mini-LED could be marginally better on a larger (and lower PPI, vs iPhone) screen than pentile.
I've owned the Tab S4, S6, and S7+. I've also been using 15.6" 4K AMOLED laptops since 2019 (e.g. Gigabyte Aero 15, Dell XPS 15, Razer Blade 15). Samsung's new 2021 SKU's like the 14" 1800P 90Hz are also not PenTile. None of these displays are PenTile. I am happy to report that if the iPad switched to OLED, there is essentially zero chance it will be PenTile.
LG's smartphone OLED displays are the same technology as Samsung's and are RG-BG PenTile. Their 4K OLED TV's are Full WRGB (each pixel actually has 4 sub-pixels and technically this is using color filters). Totally different technology.