Online modding has been a different conversation from single-player modding throughout GTA's history. Rockstar's stance has been consistent - we work through it.
Major ban waves
Recurring ban waves throughout GTA Online's life. Specific dates are less important than the pattern: when cheating tools become widespread, Rockstar issues bans.
Bans have generally targeted users of cheating tools rather than mod authors directly.
How this affects GTA 6 expectations
Same pattern is likely to apply. Online modding will be aggressively enforced. Single-player modding likely tolerated.