service mesh and domain driven design

So we have a cluster with namespaces representing different domains. Services in one namespace cannot directly talk to services in another namespaces unless routed through a load balancer. ( goes outside cluster and comes back)
We are designing service mesh for the cluster and a api gateway both of which will be in the cluster.
So service mesh allows authorization and authentication, wouldn’t it be appropriate to allow intradomain communication between services .
Is it an antipattern to Domain driven design . Should these calls to intra domain services go always through a API gateway.