On a Nexus, use a route-mapcommand with a set clause of metric-type type-[½]in order to have the same functionality as in IOS using the default-information originate always metric-type [½] command.
For example:
switch(config)#route-map STAT-OSPF, permit, sequence 10 switch(config-route-map)#match interface ethernet 1/2 switch(config-route-map)#set metric-type {external | internal | type-1 | type-2}