I assume they are welcome to use the old version, and this comes after an ignored deprecation warning. If not, then this deletion should come after a forced migration by whatever library team enforces a one version rule.

That broken build won't be pushed to production and affect users, but invisibly slowing down a production service and hoping someone notices via monitoring will probably pass tests, build fine and be pushed to production where it will affect end users. I absolutely want to work in an environment where the build fails rather than people play childish tricks to punish my users because I used a deprecated function, and hope I notice.