Perhaps, but forcing a company to change its business model like what appears to be proposed is overreach of the worst sort. If this happens, don't assume apps will be offered in both Apple's app store and other stores. There will be a mass exodus from Apple's app store and we will be faced with using Wild West apps with a higher security risk or not using them at all. This actually lowers consumer choice because it leaves no mobile operating system with a decent walled garden for security.
As I said, I could see the government requiring Apple to guarantee security of the apps in its store, so that the security benefits of the walled garden can be accrued and it is not just window dressing to gouge consumers and developers. Other than that, though, lawmakers should butt out.