The root namespace of Core is Automattic\WooCommerce, but both the blocks and wc-admin plugins exist in this namespace. In an effort to prevent possible conflicts, we should not allow for overlap in our repository. The rationale behind doing this as opposed to renaming our root namespace feels reasonable. In the case of Blocks, all of the tooling is already set up in their repository, so all blocks should go there anyway. In the case of WC-Admin, we shouldn't be refactoring admin classes, as that would duplicate work done to revamp them entirely.
Christopher Allford