Not sure why they didn't provide an identical replacement. You want to make sure they have properly trued AND tensioned the replacement wheel. I'm willing to the bad wheel was a rear disc wheel that was never removed from the bike, trued, and tensioned during the initial build. Because it's disc brake wheel where rim brake rub isn't an issue, many shops don't bother truing the wheels. They forget that high, even tension is needed for the wheel to be strong regardless of whether it's rim or disc brake. Low, uneven tension=weak wheel.
There's no reason why a properly tensioned wheel with a good quality hub and rim (such as the Mustang) should break if ridden on the road and not abused.