I don't recall if it was just for Blu-Ray solely, but they always push the Blu-Ray first. I tell you what really drives me nuts: is that Disney is famous for these 3 DVD sets, and sometimes that's the only way you can get the regular release is to buy the set, pay more money for 2 other discs I'm never gonna watch.
Extras and behind the scenes stuff are nice, but I don't need a whole other disc of them, and with my time these days, I'm lucky I have time to watch films let alone extra features so it's not a priority for me anymore.