Well if you're distributing requests over multiple servers, I wouldn't call that a monolith.
It's like saying "this thing says it is built as a suspension bridge, but there are ten of them, so I wouldn't call it a bridge."
[0] https://docs.microsoft.com/en-us/dotnet/architecture/contain...
This would also mean that deploying a microservice architecture onto a single server, using docker for example, would be considered a monolith. Or even better, any application that leverages a database on a separate server is no longer a monolith! That's way easier than rearchitecting your whole app.
I've never come across a definition for monolith in the context of software that had anything to do with the actual infrastructure employed