The Crains article had a good outline of what happened, including quotes from Duggan saying how big this is for the city and what a loss at the Supreme Court would have meant.

"Today, Chuck [[Raimi) won the biggest lawsuit. We had a law firm in this town that didn't think you should be able to collect income taxes on the work being done in the city, but the Supreme Court today unanimously ruled that our income tax collection process was being done legally," the mayor said. "Had we lost that case, it would be far more financially devastating to our future than anything that's happening with COVID-19 and I deeply appreciate that 7-0 vote of the Michigan Supreme Court …"
Here is a Freep article if you don't subscribe to Crains