Earlier quoted context omitted.
I didn't think the Barbie movie was that unexpected. It was a thinly veiled attempt at making Mattel seem authentic (in the corporate marketing sense). It's just a step up from having a snarky Twitter account to "connect with a new generation of customers". (How the movie portrayed Mattel's founder is proof of how the movie is just a brand update and far from the piece of art some say it is).
If you look at the entire history of Barbie media, the new movie is a complete departure in terms of its tone/approach/etc. You may not have liked it, but it was definitely a risk--there was a decent chance of it being a bomb that tarnished the entire brand, but it seems like the reverse happened.
Agreed, it was unexpected for Mattel. My issue with the movie is that it's corporate whitewashing and people are just eating it up. But that's just the way of the world.