2021 Yukon

3 day old 2021 GMC Yukon XL Denali with 100 miles engine stopped going 50mph on a hwy. Dealer thinks it’s a broken valve spring which impacts wide range of GM 8cyl engines. See service bulletins and recalls on various web discussions on this and few other serious issues on 2021 Yukon. Such a disappointment after coming back to domestic manufacturer after 20 years of a dozen+ trouble-free foreign car experiences. Anyone else already went through this experience? Were there engine damages? Thanks.