Its a customer retention scheme. If you're a customer of bank A and you're being flooded with ads from bank B, C, and D about greenwashing and being where the cool kids hang out, the simplest way for bank A to compete with B C and D is spam their own customers with greenwashing and aspirational stuff.

Put another way, I don't know who your banks competitors are, and you might not, but your bank thinks its competitors spam campaigns currently revolve around greenwashing and aspirational, so thats the kind of retention spam they send.