Rockstar Games usually sends out feelers, in the form of surveys, to find out what the public thinks about certain potential features that could be added to Grand Theft Auto Online. In one such recent survey, the developers of GTA Online sent a handful of GTA Online players to pick their brains about potentially adding fast travel in GTA Online.
Specifically, GTA+ members received a survey invite together with an in-game GTA$ reward for completing it. The survey doesn't stand out much save for two simple things: the mention of fast travel and access to existing Rockstar Games titles.
Rockstar Games hasn't mentioned these possible features at all in recent times but fans have a couple of theories. The prevailing one is that Rockstar might add some form of fast travel to GTA Online that is exclusive to GTA+ members. But, if this happens, we can expect backlash. GTA+ is a premium subscription that requires a monthly fee. By locking the fast-travel feature behind what's effectively a paywall, Rockstar is setting an awful precedent for future Rockstar Games titles, including GTA 6.

