As with routes of feedback on console accessibility, knowing how to get in touch about accessibility information on games is a common source of frustration, particularly as gamers do not always understand the platform/publisher/studio relationship, let alone first/third party studios and so on.
So providing a well-publicised high level service to gather accessibility feedback at a platform level and ensure it reaches the right teams would be extremely valuable.
Providing a means of contacting developers directly through digital storefronts would also help.
Electronic Arts’ accessibility feedback twitter account
App support link on iTunes