there is NOTHING that connects V with MP3
Rockstar crews connect Max Payne 3 and GTA Online. The use of GTA V and the creation of Rockstars official crew system were used very heavily in the promotion of Max Payne 3, I dont know how many times it was mentioned the crews & rivalries carry over to GTA, which confuses me as crews mean nothing in GTA V compared to MP3... there arent even any leaderboards.
Back in MP3 it was non-stop crew vs crew gang wars, get your guns out and fight , no tanks no prison thugfights bullsh*t, no waiting for lobbies to fill either.
And the crews that came out on top of all these nonstop daily ongoing warfare got all the recognition and glory.
Now its all about who can make the best youtube video or who can take pretty pictures of butterflies and deer that get featured on the newswire.
Not to mention the CEO of Rockstar Games The Benz said in an August interview flat out that high level players in MP3 would be rewarded for their ongoing support of the game and crew system.
The silver skull mask we have in GTAO is quite similiar to the social club exclusive mask unlocked for Max Payne 3 multiplayer, I suspect they just unlocked it for everyone in fear of the bitching that may ensue.