Another user showed the Oreo update, presumably from Nougat beta, at 724.9 MB. Guess this is just an MM update.

This is the previous YouTube tv update. Nothing new..

latest stock build 1901 for MM. Feb 2018 release

If you are on Nougat beta, it will fail on install

False alarm. It's still 6.0.1 and at the July 1017 security patch