We have already seen devices in different device classes fail after the automatic migration. That had nothing to do with any personal documentation. having your thermostat stop working in December is no fun. 
Thermostat problems (multiple brands) Nov 2022
I’m not saying people should panic, but I don’t think it’s unreasonable to feel concerned, either, particularly given the lack of documentation from the smartthings side on what is being changed, when, and how.