They will add that stuff, i.e. more than they did with RDR2 - it's inevitable.

Unisoft have done it a fair bit with Watch Dogs, don't think anyone cares that much about it really.

The thing that rockstar are really good at is the world-building - Los Santos just feels so authentic, even if an obvious parody: Even the radio voice actors are so well casted that the voice of non stop pop (Cara Delevingne) is allegedly a cokehead in real life too!