Comment by greycol

I expect it does help with MRP and weight as well as making them more robust with no usbc drive to be worked free (especially if people try playing cabled up as inevitably happens when controllers run out of power halfway through playing). I'd expect there will be third party options to replace the cover/battery exactly how your thinking with a nice dock to put them down in for people who prefer it.

Realistically though if the cover for the battery is nice to remove/insert then it wouldn't surprise me if having a battery charging station and hot pairs of batteries to swap out is actually the nicer usability option vs cording or dock downtime (if you leave them sitting on the couch with a low charge then need to charge halfway through).