it's pretty extreme to say seo is dead.
seo is just evolving and any "expert" who just realized "hey performance traffic must be the new thing" is pretty behind or only makes money slanging seo as a product. when seo was new people jumped on it like it was a savior and for those who didn't understand it - they were taken by the parties interested in making money from it. it's only considered a fad to those who made money from the lack of knowledge. seo is only one factor of a marketing and web strategy campaign.
he has a point though, but did he just realize this? yes, of course social media is important (even though the traffic isn't big it's fairly filtered) and of course performance traffic is key - targeting a consumer demographic and conversion rate optimization is something many of the guys who left seo lacked. they are and still are puzzled when you ask them how does the traffic perform or about CRO
it's a good thing the opportunist are getting out
