I just confirmed on @corinnestokes' computer that the default is still 50/50. I think you're right about it using whatever was done previously.
Yep, I see it there as a Local Storage variable in my browser:
Here's where it's set in the code:
https://github.com/steemit/steemit.com/blob/0612e6502c79fe1561d2b68fd8421f04da27c388/app/components/elements/ReplyEditor.jsx#L172
I'll edit my post. Thanks!