Chance Miller, writing at 9to5Mac:

Unfortunately, the new iPad mini’s screen has one limitation: it
doesn’t support ProMotion, or a 120Hz refresh rate of any kind.
Instead, it’s still locked to 60Hz. This is an incredibly
frustrating decision that I can’t quite wrap my head around.

Apple touts the iPad mini’s OLED screen as offering
significantly faster pixel response time than the previous
generation’s LCD panel, leading to improvements like smoother
scrolling and reduced motion blur.

I’ve noticed that things like swiping between Home Screen pages,
scrolling social media, and system animations are noticeably
smoother. They aren’t, however, as smooth as an Apple device with
a ProMotion display, and they’re not a substitute for a higher
refresh-rate display.

Apple is very stingy with ProMotion. Until last year it was exclusively available in iPhones, iPads, and MacBooks that had “Pro” in their name. Last year they added ProMotion to two products without “Pro” in their names: the iPhone 17 and iPhone Air. Apple refreshed the $1,600 Studio Display last year but it still only supports 60 Hz; only the $3,300 Studio Display XDR supports 120 Hz. (Apple does not call this “ProMotion”.)

My big question re: the new iPad Mini is the new “acoustic display”. Miller gives it a thumbs-up:

Essentially, Apple has designed special woofers that vibrate the
display to produce low and midrange frequencies. For higher
frequencies, custom tweeters are hidden between the glass and
aluminum enclosure. Apple says this new system delivers louder
audio, “punchier” bass, and clearer highs, despite the iPad mini’s
significantly thinner design.

In practice, I think the new iPad mini sounds great. I’d choose
headphones or an external speaker for serious music or video
consumption, but day-to-day the iPad mini’s built-in speakers are
perfectly adequate. (I’d bet that this Acoustic Display technology
shows up in future iPhones too, and the iPad mini is serving as a
test bed of sorts.)