I believe that the package manager should (optionally) show a short “News” for each package that is updated.
Example: package X is updated, and the developer knows that this will cause issues in package Y but plans to fix it tomorrow. Printing this info to the screen when X is updated would save lots of troubles for many of us.
Perhaps the message could be obtained from the release description from the tags on github? This should typically contain that sort of information and would simply need to be downloaded and printed.
I’ve seen this done before in DifferentialEquations.jl. IIRC a message was put into the build script to alert people to a (potentially silent) breaking change. As such, it’s already possible and just a case of the package maintainer being alive to the issues they might be causing…