Multiplexing is a HTTP/2 feature. But as gRPC was based on an early HTTP/2 draft, it beat HTTP/2 to the punch. Thus it is likely that HTTP/2 didn't exist at the

Multiplexing is a HTTP/2 feature. But as gRPC was based on an early HTTP/2 draft, it beat HTTP/2 to the punch. Thus it is likely that HTTP/2 didn't exist at the time the statement was made and therefore HTTP/1 would have been implied.