Let’s throw away Hanzo’s bow and see if the character’s design kit and image is retained.
Blizzard likes to keep specific images and design goals in mind and won’t change them just to suit specific whims of the playerbase. That’s not the job of the players. If you’re going to that far to change up a character, you might as well just design a brand new one.
Then you have to look at what parts of her kit can be changed and what you’re willing to sacrifice in order for her to do that. You can’t remove abilities or change their nature, at best, you can make suggestions on improving responsiveness towards specific elements of her kit (lower cooldowns on Sentries). But you’re going to have to be willing to take a hit somewhere to make those changes.
Plenty of Bastion players are willing to lose damage out of Sentry in order to make Recon more viable. But Symmetra players seem unwilling to do that. And in OW2, Blizzard seems interested in giving Recon Bastion a new gun. That’s where your best hope is for Symmetra as that is the best time for a re-design; but don’t expect the concept of a hard-light builder to disappear come OW2. Or that she would become a Support-healer.
(Though on that note; don’t really be surprised by it either).
Look at how Baptiste players provided feedback on his gunplay to improve it to a more favorable and comfortable cadence. They were willing to take a hit in his damage and healing outputs to make work. That’s where your feedback needs to be; not trying to change the dynamic or the kit; but improving on existing elements.
Many Symmetra players are unwilling to do that.