I think only when people stop wanting to see each other in person or when more people find less free time on their hands will LAN parties ever die. The author of that article claims that CSGO is the last he's played,
but there a fair amount of modern or enjoyable lan games to play, and that's disregarding non steam games like gang beasts (which might be on steam now) or console set up tournaments like FIFA, Super Smash Bros or Mortal Kombat.
In that article far too much emphasis was put on the types of games and how they're played and not why they're played. Unless you're a really terrible person I don't think any of us have gone to a LAN with prime reason to experience lag free competitive play; I hope I don't speak for just myself when I say we go to meet, greet and be merry with each other in a way that is impossible to do over mumble.
Decent lan FPS games might be dying. But that's only because the large number of lan timeless classics (CS, UT, Quake, TF2, ect) are seriously hard to beat in terms of competitive balance, quality and fun.
For the record, and to sum up my feelings about that article, I've often found "polygon opinion" is synonymous with "polygon baiting for comment"