Nightengale
Member
Considering Halo wars 2 has several trailers that surpassed 5 mio views, I am not sure if the views mean much, when it comes to sales. I think it's just one aspect of many, so it can't stand by itself, but good reviews and impressions all around as well as making people aware and interested are all contributors to games selling well.
View/Like ratio for Halo Wars 2 was below 1%, which means a lot of the views was boosted by ad views.
Any trailer that has <1% view/like ratio are high suspects for view-count boosting. Unreliable at that point.
Tldr; MS was artificially boosting the view count for some of their trailers via ads.