"The point [..] isn't about disk savings as much as minimizing dependencies and surface area of attacks such as for glibc, bash, and OpenSSL in the past several years."
Technically they didn't say specifically how they would minimize surface area of attacks, so my assumption that they meant only by minimizing dependencies (seeing as their comment was followed by a list of dependencies) may have been faulty. Thanks for letting me know that in such a kind way.
Removing outlying code that could be used as part of an attack can be useful for complex attacks. But they are essentially outliers - the actual code that you are actually running and is the actual target is still there, waiting to be pwnd. The time you spend trimming fat can often be better used to actually harden a system's access control or policies/procedures, perform auditing, etc.