It seems like if you activated developer option (setting -> about phone -> tab build number 7 times -> developer option), OTA MM update get blocked.
I tested with two Stylo phones (mine & my wife's). She immediately got MM update after 10L patch because hers not rooted + carrier locked + developer mode locked. Mine had developer option unlocked, even after 5 days no MM update.
So I KDZed again, this time didn't touch anything immediately checked system update only. 10J, 10L -> MM boom.
Now I have MM on my stylo
TL DR - Do not unlock developer option, just straight go to system update and apply patches and updates.