Anti-magic stealth nerf?

Maybe I'm just still reeling from the previous nerfs we've gotten over the past few days, but did Anti-magic shield get a stealth nerf recently?
Has the tooltip always said "to a maximum of 50% of the death knights health"? I could have sworn that not even a month ago I could tank nay instant kill magic abilities with it and be fine, abilities that should have done 50% of my health easily in one or two ticks.

Please tell me I'm wrong. I really can't stand to see us nerfed any further.
That was implemented in 3.1.0.
Thanks,
Don't know why I didn't catch that sooner, but I'm relieved either way.