The release is marketing, both to customers and for hiring. I have zero doubt they made this because they're using LLMs themselves, not just faking it like for fellow kids.

LLMs are valuable to all companies of any significant size, just for knowledge management. Then for a bank specifically, there a ton of text classification and summarization tasks when it comes to expense management, bill pay and all the other services they offer. There's also internal stuff. Fraud and KYC would be helped a lot.