According to the trendlines on op.gg, Sona was at a winrate of about 52% at patch 7.23
After that patch, it plummeted by about 5% down to 47%, where it now sits at exactly 46.99%.
She went from having the 8th highest winrate out of all supports, to the 25th, and she has been like that for about 3 patches. Nothing has been done to help, she's utter garbage now. Maybe with the new AP item changes she'll be a bit better, but I'm not hopeful after the changes they made to her.
She went from being decent/good, to being utter trash.
Everyone else seems to be sitting at a healthy winrate of 50%, except for Morgana who I now see going mid more often, and Karma who I don't even know what she's supposed to be. Mid? Support? Who knows.
But poor Sona has been in the dumpster for 3 patches after being pretty decent, and I'd like to see some change to that to at least bring her up to 49-50% like everyone else. Same with Morgana, who could also use a boost from her current winrate of 46%.