‘[The performance of] the monitors will suffer’ is implicated here.

You value precise and simple language, but other people value other things like clarity and brevity. It’s a tradeoff. Making something precise can mean adding extra words which sometimes, paradoxically makes it less clear and more difficult to understand. Even in extremely formal contexts like mathematical papers, it's inappropriate to be completely precise because it gets in the way of communicating ideas. And if we strongly preferred simple language, we would use https://simple.wikipedia.org/ instead of https://en.wikipedia.org/

The original statement is clear from context, since the literal meaning is semantically impossible (monitors are incapable of suffering).

>Thank you for the link, it is very interesting. Having read the Wikipedia article, I think that metonym here is a bit too heavyweight for the simple thing expressed in the comment.

Metonym is just a linguistic term. Such terms are not constrained to describe high uses of language by great masters of writing. They are merely names for specific constructs or linguistic phenomena.

A drunken sailor swearing at someone at 3am could be using a metonym just as easily as Wallace Stevens.