This occurs in org-compat.el:
(eval-after-load "flyspell"
'(add-to-list 'flyspell-delayed-commands 'org-self-insert-command))
By not using a package symbol, this code runs whenever any file named
flyspell.el is loaded. Guess what one of the :checkers spell module's
autoloads files is named? flyspell.el
bfd71a8bb9