That very much depends on implementation.It's not that you do or not. If it's made into law, you and everyone else WILL have to deal with this. You can't not have the side loading ability if the phone/iOS can do it. It's there if you want it or not, use it or not. We are all affected by this.
This system is trying to give the consumer choice. But in fact they are taking away my choice. I can't "not" (double negative) have side loading's vulnerabilities affect me.