You're on the right track but your logic is faulty;
Kaby lake was the current for laptops right up until it was superceded by Whiskey Lake on August 28, 2018; barely 3 years ago. It would have taken 2-3 months for Whisky Lake silicon to be integrated into laptop models, validated, shipped out to distributors and sent on to retail/etailer shelves and available to buy, so realistically the state of the art was still Kaby Lake right up until the holiday season when new Whiskey Lake latops would have been rolled out (probably rushed out) in time for Black Friday/Cyber Monday and Christmas.
By not supporting Kaby Lake, Microsoft aren't even offering support for Intel laptops beyond about 2.8 years old which will be closer to 3 years for Win11's official launch.
When talking about hardware support, you have to remember that the "current" product cutoff happens when it's replaced by something newer, not its own launch date.