Maybe? I don't think you're wrong, but I think all of those have reasonably easy explanations if you assume that Apple genuinely believed they had a good design

Maybe? I don't think you're wrong, but I think all of those have reasonably easy explanations if you assume that Apple genuinely believed they had a good design that just needed some tweaking to correct, and I think they genuinely believed that. There weren't new designs in the pipeline that used fundamentally different keyboards. There weren't designs in the pipeline that went back on "all you need is USB-C." (I wouldn't be at all surprised if they stick with that, actually; it's conceivable that the 16" MBP that's rumored as their next release will add back an SD slot, but I'd be a little surprised if it adds back a USB-A port. I also expect it to continue to have a Touch Bar, although it may add back a physical escape key.)