99% of the time when I use stash, it’s ”stash” or ”stash pop”, usually with ten seconds or so between the two. It’s very easy to remember.
Your alternative, on the other hand, uses an obscure flag to cherry-pick. What scenario would you use that flag for, except this particular one? How is remembering that flag any simpler?
Also, I don’t think your sequence of commands is correct. First, ”git branch” doesn’t switch to the newly created branch, so ”WIP” would be committed on your original branch. Second, the argument to cherry-pick should be a reference to the commit rather than the commit message. I believe a correct version would be:
git switch -c my_stash
git commit -am WIP
git switch -
git pull
git cherry-pick -n my_stash
git branch -D my_stash