I doubt the contents of spire of dawn will be removed from matched play or anything like that. Yeah, the box was released in late 2010 BUT with the repack for AoS and the fact that all those sculpts were new at the time (going back to the cost of the design and moulds to make them, coupled with the fact that the cost of the set was a freaking steal), I think they still have some life in them (hell, khorne bloodletters were made in 2007 and still kicking).
If your problem with playing is a lack of battle line options (I think you mentioned that), then for the time being I suggest just getting some stormcast liberators for that role and wait it out. I really do think that we'll see tyrion's dudes soon after the slannesh release