Reuse Blocks are not translated as the reuse methodology is somewhat different between the DC-Exp and the EE flow.
Logical-only reuse blocks for example do not exist in DC-Exp. Constraints are not preserved.
This is why you need to extract each block, translate the design and check them back in as reuse block in the EE central library or DMS.
More information should be available in the migration planning guide on SupportNet.