I've been reading this: https://tcrf.net/The_Legend_of_Zelda:_Majora's_Mask/Program_Revision_Differences
In the Japanese versions, there are three save files, whereas the American version restricts you to two. This, however, comes at a price: saving at Owl Statues is not possible at all in the Japanese versions, so you were required to use the Song of Time every time you wanted to save the game. Apparently, that turned out to be really annoying, so Owl Saves were added to the American version which necessitated removing the third save slot.
These [owl statues] were added to accommodate the new system of saving at Owl Statues that was added for the American release.
Did the original game not have owl statues at all? I thought that those owl statues also indicate the spots where you can "soar" (teleport) to. So in the Japanese version, you just "soar" to random locations with no object indicating the "magical spot"? Or are they there, just that they cannot be used to "save and quit"? If so, the page linked to is wrong.
Why, as it says on the page, would having owl statues "necessitate" the removal of the third save slot? That makes no sense to me.