I'd love to hear the reasoning behind that choice if it's Rich Hickey that did it, since it's called some and every in Common Lisp and he's written a great deal in that language.
The names were chosen by Rich. Many choices were considered and they all had pros and cons. The new some?/if-some/when-some functions follow the "not nil" notion in "some->" (but break with the meaning in "some"). Naming is hard. :)