Restaurants now work in Sulani.
Fixed in Patch 1.54.120
I've been working on getting a restaurant going in Sulani. As Crinrict noted the employees need to be local.
I've also found that it works best if you pick a lot where Sims spawn near the lot. If your employees spawn too far away from the lot they seem to get a bit stuck. When I sent my Sim home her Host was idling at the exit point. This happens occasionally in Windenburg as well. It usually helps to open the restaurant for an hour or so before taking your Sim there. Not always good for the "ratings," but usually helps with the employees being there.
LittleMsSam had a hiring mod, but I'm not sure if it's been updated for IL or if it would help with hiring local.
Marked as Solution for Visibility. This is still an open issue.
Here's my blog post with a workaround: https://sims4.crinrict.com/eng/2019/06/restaurant-employees-do-not-appear-in-sulani/
