Good point on the Apple Pencil.I see it as being linked to which Apple Pencil the device supports.
The original Pencil requires a Lightning connector to charge it whereas the Pencil 2 requires the additional Smart Connector, which will increase the cost.
I'm currently iPadless although I used to have a 10.5" Pro. I liked True Tone, but it was hardly essential. I didn't really notice the benefits of Pro Motion.
I immediately noticed the lack of a laminated display when helping a family member out with their iPad Air, but I don't think it's a deal breaker.
I agree with you on Face ID. In terms of features, having four speakers would rank ahead of that for me.
The laminated display with anti-glare coating is a nice thing to have, but the benefit is partially lost on me because I put a tempered glass screen protector on all my iPads.
As for the speakers, 99% of the time I use headphones anyway, so it's less of a priority for me, and I see the speaker count as a real world cost measure and differentiating feature between the consumer and pro lines, that people actually understand. Most people don't understand the point of a laminated display or Pro Motion, and barely understand/care about True Tone.