It's a good question, but the article claims there's a compensation: "when connectivity between the hemispheres is high, connectivity within each hemisphere is

It's a good question, but the article claims there's a compensation: "when connectivity between the hemispheres is high, connectivity within each hemisphere is relatively low, and vice versa". There's no reason that couldn't apply to someone with a split brain or a single hemisphere, at least after given time to adapt to the surgery.