If magic does return to SB I’m pretty sure some epic craziness is gonna go down. Not only will we be able to see more of magic in SB, but hopefully people will start acting like their old selves. From where I stand, there’s a good and bad side to this.
Good:
If Emma were able to see everyone’s real identities resurfacing, it’ll help to convince her even more that FTL and it’s inhabitants are real. Gold might not only be able to “work some magic” that Emma could actually see, but might start reverting even more back into his old crazy, impish self. Maybe Emma will get to hear his iconic giggle? 
August’s transformation back into wood might stop, and Jefferson might be able to use his hat to it’s full extent. And yes, I really want Jefferson to get his daughter back. 😥
Bad:
I also asked this question in another thread if anyone else thought that having people remember their past lives could have some bad consequences. While this is possible, throwing magic into the mix would just make it worse. People would remember their old grudges, and fights could break out. We might even get to see Moe French leading an angry crowd of people with torches trying to burn down Gold’s house shouting “Kill the beast!” 😯
Even worse, it might hold up Gold’s search for Bae. The guy’s addicted to power, and putting him in a situation where he would be able to use magic again would get him sidetracked. It’ll be like dangling a piece of candy in front of someone with a large sweet tooth. And since Regina has the feeling that Gold wants the curse broken, he might take a chance to use magic again just to keep her off his back.