Can speak on how to prevent it. Best to stop automatic app updates. Also iPhone 5s’s are very cheap and do not support newer versions of the app.
I was always manually updating my apps and never updated the WM app but either it auto-updated at one point or the change to the financial services section isn't directly related to the update itself. Either way, I have the new version now.
I'd add that a lot of functionality was removed from being directly in the app to sending you to a webpage, such as any pharmacy functions (refills, RX lists, etc.)