Lana was underbilled as a secondary headliner to begin with - which is clear given the stadium tour she's sold!
Chappell very much the same I reckon, she would be able to shift that Lana tour honestly i think
I don't think it is at all and her being at Sziget seems very unlikely to me. Checked the profile, there are are a lot of tweets that turned out to be fake so don't trust that account.
Also, I am a fan of house music, but this year I mostly see techno on the lineup, especially 'I Hate Models' or '999999999' type techno. Last year we had Four Tet, Fisher, Barry Can't Swim, Dom Dolla and I really hope to see more artists like that if we are getting more house, and less techno DJs