The Big Sur UI being more spaced out hints at it. The fact it runs iOS apps unmodified only really works flawlessly if the user can touch the screen otherwise there will be some multitouch functionality only phone users can use and would require devs to put in extra work.
Most of the rumor mill close to Apple (John Gruber, atp.fm etc) all believe it's coming.
The devices (iPad/MBP) are clearly starting to converge and I think the next MBP is going to be genetically closer to an iPad than it is todays MBP, you can tell they've been leaving a ton of enhancements out of the current lineup waiting for an evolution, MBP lags behind all other premium laptops in webcam quality, LTE, touch support, pen support and screen bezel and the ARM transition is definitely the time to push this evolutionary update.
iOS apps: but consider how Apple added (is adding? I don’t use the ecosystem) a pointer to iPadOS. That’s heading towards apps not requiring touch for interactions.
Webcam quality: I dunno, most expensive laptops I’ve seen also have lousy 720p webcams. (I have a Surface Book, which is more like a tablet in this regard, having both a front- and a rear-facing camera, both fairly decent.
LTE: not particularly common in laptops. It’s always been niche functionality.
It has always seemed weird to me how much of a schism there has been between tablets and laptops in things like cameras and LTE. (Microsoft are the ones that started tearing down the dividing wall of partition in the Surface line of products; but it’s still mostly intact.)
I’ll be interested to see what comes of it (though have no plans to ever acquire any Apple gear).
Most of the rumor mill close to Apple (John Gruber, atp.fm etc) all believe it's coming.
The devices (iPad/MBP) are clearly starting to converge and I think the next MBP is going to be genetically closer to an iPad than it is todays MBP, you can tell they've been leaving a ton of enhancements out of the current lineup waiting for an evolution, MBP lags behind all other premium laptops in webcam quality, LTE, touch support, pen support and screen bezel and the ARM transition is definitely the time to push this evolutionary update.