Hi Noam,
I ended up here as I also noticed a big difference in emacs-lisp indentation.
Your patch fixes the multi-line string indentation. Thanks!
But indentation is still broken in cases like these:
(with-eval-after-load 'foo
(setq bar `(
baz)))
It instead indents to:
(with-eval-after-load 'foo
(setq bar `(
baz)))
The "b" in "baz" is lining up with "'" in "'foo".
Reverting lisp-mode.el to that in commit 66dc8dd66dc8dd fixes the problem.