Banks sole business is making money by managing others people money, consequently I do imagine that they estimate that whatever they put online is safe enough and insured enough not be pragmatically speaking creating any risk for their consume. I imagine, and maybe naively so, that it’s a well enough regulated business so that if “shit happens” it’s on the bank to cover, not the customer.




They can revoke usage. Say if you use app version 7 and the required app is version 8 then no transaction can be done. The app can be installed yet unusable. So it’s not because the app is installed and outdated that functionalities have to remain usable. Gaming servers do that all the time.
I’m pretty sure they already do that, not “just” warnings.