Shuri has been Black Panther in the comics. No reasons she couldn't in the MCU.
But they sure hell better not recast the character.
I'm in favor of this as well. Although it will be awkward to explain in-universe what happened to the original Black Panther. It's like when Married with Children had that pregnancy plot, and all of a sudden Katey Sagal had a miscarriage. Chadwick's death is going to be hovering over Black Panther 2 and there may not be an easy way to adapt the story. I hope they don't do some awkward digital double.