I would expect them to say hey, now that you've got so much more capital in your account I'd like to set up a short meeting to learn more about your company. Then they meet with you, learn a bit about your business trajectory (for their own planning) and pitch some significantly increased benefits to keep you around.
You don't have to accept, but they should at least actively try to bring you in if your account is a bug or important one.
There are plenty of ways to get you in the conversational door like offering a better rate or to help protect the account.
Eventually someone from hashicorp "...notices we have ~$35M sitting in cash in a Chase bank account. This is obviously not a smart thing to do, so he suggests some financial plans for how to better safeguard and utilize this mountain of cash". The bank could have been the party to preemptively explain this to the author, and if they did they might have been able to be a part of the solution (or at least try to negotiate for it) instead of losing the entire account.
It sounds like the bank manager was being too delicate, asking the author if they had any banking needs when he didn't really think he had any. They should have been more blunt and said look dude you have a ton of money in here, you're probably not used to managing this amount of money, we need to take just a bit of time to discuss it and we'll make it easy and worth your while.
