The AA rumours started from MAG frequently visiting Dallas to have talks with them about re-commencing STN flights. The Qatar rumours came from the Hotel being built opposite Sat 1.
I also doubt either of those airlines will start but I think 2017 will see a launch of a scheduled long-haul airline.
And with regards with the £80m, I think it has been been woefully spent. WDF and shopping/restaurants look nice but the design is awful, the choke points that exist in the terminal cause overcrowding and the shopping centre experience is not enjoyable for passengers. When they want to compete with LGW and LHR they need to seriously look at the terminal design again. Sat 1 already needs a refurb updating the refurb, it's falling apart if you look close enough. I do agree security is however much improved.