Stealth Ward 'Bug Fix'

I had read over the patch notes last night, but somewhere in the list of changes I failed to notice that stealth wards got a 'bug fix.'

While playing my first game as Leona I was sitting in lane brush waiting for those trinket wards to come in so I could get some lane dominance. Much to comedic value, blitz crank threw down a ward right on top of me and... AA, Q, and whiff. It disappears. I get grabbed and hurt for nothing.

I don't see how this is a 'Bug Fix' when this has been in the game for a long time. Not that renaming it to an adjustment would help anything. What was the design purpose for fixing this, and, why fix it after all this time?