Valorant's viewership comes watch parties. Shroud gets twice as many views as the main stream and they partnered with him, myth, pokimane, and two others to stream it. Not to mention there was a lot of generated hype around the tournament due to it being it's first major tournament and first LAN. It was bound to do good but I would imagine without shroud, the viewership would have probably been like 500-700k which is still good. Valorant just had a lot of generated hype around it. It's not surprising.