I just read a post from Meddler suggesting that the Sona changes would go through to live the next patch. But judging from whats been on PBE so far...I just don't think it would be good at all.
I personally have a few major problems with the rework, as a longtime Sona player, which I hope will factor into your considerations:
1. The **rework forces you to stand next to your ADC all the time in lane** to make better use of your skills. One of the most fun aspects of live Sona is being able to zone out in front while your ADC hangs back CSing. This fun aspect of her seems to be discouraged by the changes, where it seems you should literally just follow the ADC around as they CS to give them the bonus effects. Not that fun at all.
2. **Q auto attack boost** is really hard to notice, especially for an ADC CSing. More often than not, it will probably just get used up on a minion, making Sona feel a lot more frustrating to play. The auto attack boost on herself also just seems like a weaker version of power chord, which makes it so that Sona basically plays the same whether she has power chord or not.
3. **Relies on allies knowing about your skills more than anything.** I already mentioned the Q aa boost, but with a team not familiar with Sona's kit and standing apart, PBE Sona is helpless. It feels like most of the control over Sona's power comes from how her allies make use of her, rather than anything Sona can decide herself (moreso in PBE than live, since the "aura" ranges are lower, less power chord interaction and again, Q attack boost)
Again, please take more time with this rework. Right now, most of the responses to the changes seem to be negative. I'm sure other Sona players have a lot to say on this matter, so listen to them, make some big changes, gradually perfect them, and soon playing Sona will be a much more enjoyable experience!