Here is Mr. Happy's video discussing this:

https://www.youtube.com/watch?v=AvffqCc30H4&t=0s

I believe this was posted around 4.3 iirc, but should still apply. He emphasizes that rez immunity protects against most attacks, so it would make sense that curveball attacks will ignore the immunity.

I don't foresee the devs changing this, otherwise they would have likely done it already.