Not necessarily. That one can have these tools in-application doesn't mean one cannot combine this with some form of RPC as well. Especially whether one needs load balancing or not seem to be a completely orthogonal issue.
On the other hand, why not a monolith and single instance? If one uses a performant language one would be amazed how much can run on a single machine. If one expects growth one should have some plan to scale, sure, but if one does not go for shenanigans like running queues and the like between applications using some form of RCP one might get amazed how much your single monolith can actually do. All this extra networks stuff and so on is not exactly free.
