If someone has pearls, they can get away from combat easily regardless. It was the same with the old system of 50 block warp back to over world, everyone (including me) would just throw one over a mountain and /world.
They can still enderpearl in, but they'd better have damn good aim. A botched throw means getting stuck in the webs or a firey death on the roof. Most wouldn't attempt it until they were very close.