Was Dancing Queen really filmed in 2008

I'm having trouble believing that dancing Queen was actually filmed in 2008 for a number of reasons

1.Gee got released instead of Dancing Queen right? Well there is clearly a big difference in camera quality making me think that Dancing Queen was filmed Mehr recently

2.Everyone looks pretty much the same as they do today (some with Mehr make-up than usual and some with less)

3.Their voices sound so much better than they did in 2008 such as Yuri, Seohyun and Yoona.

But then again I think it could've been filmed in 2008 because

1.Jessica's teeth are back to how they used to be, now they're much straighter

2.Sunny has long hair again (possibly a wig)

But really I think that they just put no make-up on Sunny to make her look young again and no make-up on Seohyun's eyes. I think they mixed up the hairstyles to make them look young again (and also for the speiselokal, diner theme) and all they did was just re-record the song and re-film it then release it. What do Du think?