I saw the @Wizardsardine guys posting about this, so I suspect it is more than just a random PR.
Miniscript is a pretty cool. Check out this Optech article by Antoine Ponsoit or this BitBox Swiss article.
Basically, it's a set of bitcoin script formulas that are known to be safe and well understood so that they can be condensed into a shorthand that is easy to reason about.
While there are a number of wallet apps that support miniscript, if you want to use those apps with a hardware device, the device also needs to support miniscript.
So far, the lost of hardware devices that do is BitBox Swiss, Coldcard, Jade, Ledger, Spector DIY, and krux. There may be a few I missed, but I don't think so.
Trezor has pretty big reach, so this is a cool improvement.
Miniscript on hardware wallets is a bigger deal than the headline suggests. It's the layer that makes multisig and timelocked inheritance setups actually usable for normal people, not just developers hand-crafting scripts. If Trezor ships this well, it could quietly become the on-ramp for serious long-term custody without needing Casa or Unchained.
I sure hope Trent reznor is getting a mini script too