Would that not be a concern for most computers? Aren’t most of these motherboards manufactured in China (or at least close proximity to China? Taiwan, Korea, Japan, Vietnam, Malaysia, etc.)
But older Thinkpads (not sure about newer (~5 years old) ones, certainly not brand brand new models) have great support of alternative firmware such as coreboot and libreboot, other projects that disable Intel ME and the like.
It's the firmware that is made in China that's problematic, not where the motherboard is soldered. Framework assembled there, too, but use open source coreboot firmware. Doesn't get any better than that.
Almost every upgrade of firmware for my Lenovo laptop is CVEs recently. I have no doubts they share that with their government and keep some backdoors opened.
But older Thinkpads (not sure about newer (~5 years old) ones, certainly not brand brand new models) have great support of alternative firmware such as coreboot and libreboot, other projects that disable Intel ME and the like.