Yes, that's mostly for a Jill/Bella run and while it's true that if this "date" is really just a ruse to ruin things for Tybalt, the thought of being spotted isn't quite as worrisome, but think on this... It's not so much Jill that MC has to hide from. There is a whole host of people at B&R that MC would rather not discover him on a date with a teacher. Unless you are doing an extremely faithful playthrough for your chosen girl (and even then), MC would have some explaining to do. And as I've said before, DPC would just love to have some random B&R person (not just LIs) happen to walk in to that exact restaurant at that exact time just to cause drama. Be it Jade, Stephan, Sage, Quinn, Nicole, one of the Jocks, just about anyone. Even Chad or Troy could walk in see MC and Bella and if you're not on good terms they could say, if you reveal our secret, we will reveal yours. Maya and Josy may not be bothered that much now, but it could play into their jealousy stats later on when the threesome begins to fracture.
MC has already been taking chances by posting bikini Bella to Rooster, inviting her to the DIK house, and being photographed with Bella in her nightie, on a Sunday morning at her home! (and clueless Jill posts it to Rooster
) Being caught dining out (with Bella dressed to the nines) would leave no doubts. I think MC and Bella's open actions in their "relationship" have been one of the most baffling things to me. At least fellow teacher Jade takes some reasonable precautions. Bella is just like fuck it, Imma do what I want. Consequences been damned.