There are always those specific cases you need to do when upgrading major versions. The chance of a percentage of 14 microservices just plain not using that fe

There are always those specific cases you need to do when upgrading major versions. The chance of a percentage of 14 microservices just plain not using that feature is bigger than the chance of that monolith not using it. A completely contrived and fake example: The language you're using has a complete refactor of its math library, everything must be rewritten in a new style that's incompatible with the old style. In a microservice world there's a good chance that very few of those actually need the high-powered math library. But your monolith has a few sections that use it so the whole shebang is delayed until that bit is rewritten to the new API.