The 3DS and PS4 double pack feels wrong... but it does look quite nice. I guess it makes sense given that they are two different versions, and we are talking about Dragon Quest in Japan.
I'm not really sure what to make of those comments regarding the Switch version. I'd have to think Nintendo would be pushing for it to launch on July 29 as well, as it would likely be a huge boost for Switch hardware sales (though it sounds like Nintendo isn't having much trouble selling through shipments in Japan right now as it is). I can think of some reasons why Square Enix would want to release it later, but then why leave a July 29 release date on the table at all? Maybe it's just as simple as them not knowing if it's going to be ready in time at the moment. Some people also seem to think that Nintendo wants to announce it themselves during today's Nintendo Direct (at least the one that airs in Japan). I guess we'll find out soon.