Well, the welds between the aluminum and steel on the thing could crack wide open.
When I read that they were going to weld aluminum and steel together, that was what made me dispense with any further support of the idea. There are some ideas that are just so stupid, no more information is necessary.
They are trying to save top weight. Galvanic corrosion is well understood and sacificial diods are necessary. This is done in pleasure yachts. I think the brits did it on type 42’s. But again they are virtually unarmored. Is that smart for a warship that is expected to dogfight with smaller craft and take on shore batteries?