Shoot, there went down the drain my plans to visit SEA... had award return from there end of September.
Contacted WA and they offer rerouting only on their own flights, so not a connection from SEA to LAX/ORD/DFW/JFK.
So LAX it is and now waiting if they can confirm it.
Reason for cancellation maybe is also the fact that one 333 is going to Australia beginning of October....