Yeah, it's a great start that will force more accountants to understand blockchain and BTC. I just hope that there is enough qualified ppl who will educate them in formal way about it. Atm I'm noticing more and more companies running training for those individuals but they are not doing it properly (still to high tech for most ppl)
First of all why would it matter how many BTC are in circulation or have been lost? The less BTC there is the more valuable those in circulation are. This idea first of all would not work and finding Satoshi wont make any difference - if anything it could damage whole idea. It's better to focus on building BTC adoption than tempering with blockchain.
You're banker is super wrong. For example in Poland there is a coalition of banks using DLT on already working system for instant payments - called BLIK. It's already working in most shops where you just press one button you gen 6 digit code, than cashier puts it in on their POS and you jest click again to accept payment.