Materialized view is introduced by 3bf3ab8c563 and at that UNLOGGED was allowed, and it is disallowed by another commit 3223b25ff73. However, it seems that the tab-complement is missed to fixed.
The Assert for RELKIND_MATVIEW in heapam_hander.c was introduced in d25f519107b after that, but I think it can be also removed.