I hope I will never have to rely on a bank that uses this architecture. It seems they are vastly underestimating the complexity of distributed systems and the range of their failure modes. It's all cool if you're building a web site, less so if it's about your money and being unable to pay at a gas station.
Everything around that (trading models, development, research systems, reporting) can be microservices, but it will all rely on the core system.
It's just that rather than have a single monolithic app in front of it they have broken it up into a suite of smaller, independent services. And many of those services will have their own database which contains a transformed, optimised slice of the total EDW data.
You seem to be implying that you know something that the very talented developers I worked with don't. Be curious to know what that is.