Certainly Julia will cache more compiled code in the future, as well as other techniques to decrease load time. Implementing this takes time because Julia’s dynamic nature makes it tricky, but the Julia developers are well aware of the desire to improve load times and are steadily making things better with each release.
This has been heavily discussed (e.g. see Roadmap for a faster time-to-first-plot?) and it probably isn’t productive to discuss it again. Meanwhile, see this post for how Julia users typically avoid it now simply by using long-running interactive sessions: Time to first plot clarification - #2 by stillyslalom