It's more nuanced than that. When I flew out of MIA three weeks ago, a TSA agent asked to remove and run my iPad separate from my bag because I had a bunch of "clutter" (other electronic junk) in my bag. With the same level of bag junk two days later in TPA, I didn't have to remove it. At the same checkpoint at MIA (but with different agents) one week later, I didn't have to remove it.

I've never had to remove it from the case though, just the bag.

It behooves you to keep the iPad easily accessible anyways, since it's a very convenient way to pass time in lines or sitting down.