I am not a member of the Clojure core team, so cannot speak for them, but I can say that they definitely value backwards compatibility of behavior for core functions. Given that the current behavior of `partition` has been the way it currently is for at least 10 years, they are likely loathe to change its behavior, in case any working code out there relies upon it, in all of its details.
If that is the situation, then the core team is far more likely to consider changes to the documentation that clarifies this existing behavior, rather than changing the behavior.
There are also sites like https://clojuredocs.org/clojure.core/partition
that allow community-contributed examples of behavior of core functions, with comments explaining it, that allow far more extensive examples than most Clojure core functions will likely ever include in their doc strings.