There was a presentation at the last Linaro Connect by someone working on Centos. He specifically discussed the specific addition on the BSD license related to the FAT driver. Furthermore he mentioned that the Red Hat / Centos legal team reviewed this and found no concern for including Tianocore as part of Centos (and I assume Red Hat too as both products are very similar).
Note ARM64 version of Centos has a hard requirement on SBSA /SBBR compliance, so that probably explains their motivation to include Tianocore in the distribution.
Ronald