Getting better cameras in folds than in bar phones is way bigger issue than some pen problems. You can always carry a pen separately, its not end of the world, but having low resolution poor reach 1/4'' sensor instead of better one in the ''next gen'' form factor (foldable), for basically higher price is very sad.
Word on the grapevine seems to indicate that Samsung could be set to ditch the built-in S Pen on its phones, starting with the Galaxy S27 Ultra. Speculatively, the 2027 flagship could either launch without an S Pen at all, or with an external S Pen a la Galaxy S21 Ultra.