What is the deeper meaning behind the Good Witch of the North not telling Dorothy of the power that the ruby slippers held all along?
Given that the entire adventure was a dream, the magic of the shoes was merely a subconscious exit from the dream.
Remember, Glenda did not know the power of the slippers. She merely said they must be powerful if the Wicked Witch of the West wanted them so badly. Even the WWotW didn't know their full power, it wasn't until she got shocked by them that she realized they couldn't be removed until the wearer was dead.
It's possible Glenda later learned of their ability to teleport the user, although the reality is that it really didn't matter. Essentially, this is a case of "Why not just fly the eagles into Mordor?"; There'd be no point to the story if that happened.
There is no need to look for a "deeper meaning" to Glinda waiting to tell Dorothy about the ruby slippers' power, because she explains the meaning herself, explicitly and repeatedly, at the end of the movie (bolding mine):
Dorothy: Oh, will you help me? Can you help me?
Glinda: You don't need to be helped any longer. You've always had the power to go back to Kansas.
Dorothy: I have?
Scarecrow: Then why didn't you tell her before?
Glinda: Because she wouldn't have believed me. She had to learn it for herself.
Tin Man: What have you learned, Dorothy?
Dorothy: Well, I think that it—that it wasn't enough to just want to see Uncle Henry and Auntie Em. And it's that if I ever go looking for my heart's desire again, I won't look any further than my own backyard, because if it isn't there, I never really lost it to begin with. Is that right?
Glinda: That's all it is.
Scarecrow: But that's so easy! I should've thought of it for you.
Tin Man: I should've felt it in my heart.
Glinda: No, she had to find it out for herself.
So it's clear that Glinda knew about the slippers' power all along, but first wanted to Dorothy to understand why she wanted to go home, not just how to go home. Glinda clearly felt that the best way of bringing Dorothy to such an understanding was to allow her to experience the trials, tribulations, and friendships of a sojourn in Oz.