Maybe convert some of them, not all. And Maxis should base which they are going to convert on the in-game lore of the world in question. Like, if it makes sense for pre-mades from that world's culture to actually live their daily lives there, then make it residential. For example: I'd love to see El Selvadorada be something similar to Mt Komerebi, a residential world with rental lots and actual activities to do when renting those lots. But I'd want to keep Granite Falls a specific vacation world, because there are really no premades living there. Heck, when one of my more outdoorsy Sims, Willow, went there, there weren't really a lot of Sims she could invite to join in activities with her! Even the ranger was hard to find. People might work there, but people obviously don't live there.
On a similar topic: we need better vacation worlds, and Mt Komerebi is an example of a good one if you ask me. In my opinion, Outdoor Retreat could use a pack refresh: Willow didn't really have enough activities to do for a 4-day vacation, but also not enough time to really skill up in Herbalism after she obtained the skill. There has to be more to camping then just sitting in a tent, throwing horseshoes, roasting weenies and stargazing all alone. Because there frankly were barely any townies that spawned which she could've interacted with while doing those activities. No, really, I think I only saw two or three walking by for those entire 4 days, and one of them was the ranger. All of those activities would've been way more fun if she had met some new people, because I got bored of them so easily with nobody for Willow to talk to. And where's other small camp activities like braiding friendship bracelets, making flower crowns for either another Sim or yourself, and crafting stuff like small leather objects, etc? No need to make all of these a skill, I'd actually prefer it if they weren't. But I feel that Outdoor Retreat is really missing those small activities that made other packs good (the reminisce interaction in Nifty Knitting, rabbits in Cottage Living actually digging holes in the ground, pidgeons in Get Together actually doing the pidgeon walk, etc).