They support it to the extent it is required to support due to contractual obligations for chromebooks or other vendors who may have similar deals with Intel. I

They support it to the extent it is required to support due to contractual obligations for chromebooks or other vendors who may have similar deals with Intel. I doubt if Intel actually sees coreboot as something worthwhile outside of a shim to load FSP. To that end, they have also create a BSD licensed project called slimboot (more like shimboot) which exemplifies that approach better.