Thats definitely inevitable. Oda has made laughs extremely important in One Piece altogether. Unique laughs for tons of characters, D's laughing/smiling when they die, "Laugh Tale" and thus Roger laughing, Smiles as you said too. I do believe the D is a sideways laughing mouth/grin but also other things too like a half sun/moon too.
Another random parallel too, Monsters Inc had doors that opened to other places in the world, like portals. Blueno's fruit is kinda similar and is the door door fruit right? Coincidence? I wouldnt be surprised if Blueno could do actual full blown multi dimensional travel, hopping to new dimensions/universes with the awakening of his DF?
Good call with the doors and a good question. I was always intrigued to find out what would happen if someone like Blueno used his door door fruit inside Brulees Mirror World, for example. Would it work in there, or what about Blackbeard's Darkness Pocket Dimension? Could Brulee or Bruno escape if they were sucked into that? Devil Fruit Powers are also still a big mystery to me. We recently learned that they were created by the hopes and wishes of the people, but how exactly? We know that multiple moons exist in the One Piece world, so why not parallel universes?
I know Oda already restricted time travel with Toki's Devil Fruit to not let the story get out of hand too much, so I am not sure if he will further expand this dimensional stuff or solely use it for combat purposes. Could Blackbeard become invincible if he absorbs himself into darkness?
This is a real head-scratcher right now, but I like it. The World Government might as well defeated the more technologically advanced ancient kingdom with things like Brunos devil fruit. There are endless possibilities. It could all be a hoax, and at the very end, we might get a bigger enemy that travels through another dimension and threatens everyone. Okay, now I am getting too much into that.