Today saw the release of a small weekly content update for Red Dead Online, adding a fishing challenge to the game. We also know about four other game modes coming to the game in the next three weeks, however the next major Beta Update is planned for later this Spring. Rockstar has detailed their upcoming plans for new features, based on player feedback.

Ever since release, one of the developers' main concerns has been griefing - or, rather, the effort to minimize this phenomenon. Over the course of the Beta, new systems have been put in place to mitigate the issue, to varying measures of success. In their continued efforts in this regard, Rockstar's developers have devised the new Hostility system which will be coming to the game soon.
The Hostility system seeks to eliminate one of the weaknesses that the proximity-based blip system suffered from. Players who try to defend themselves from griefers run the risk of being marked as violent themselves, thus increasing the visibility of their blip on the map and turning red.
The upcoming Hostility system will monitor which party in a conflict is the aggressor, so victims of griefing can safely protect themselves. This way, if you kill a griefer - regardless of whether they were griefing you or someone else - your own hostility stat will not increase, nor will you incur any bounties.
Naturally, the Hostility system won't come into play when you are in structured PvP scenarios. However, keep in mind that if you are engaged in free roam PvP activities, killing other players in free roam who are not participating will increase your hostility stat. The Hostility system has additional features that will be detailed in upcoming posts.
Additionally, a new system will allow players to mark themselves as either Defensive or Offensive. An evolution of the passive mode system from GTA Online, as well as "marked for PvP" used in many MMOs like World of Warcraft, this new Playing Style system further serves to prevent griefing and unwanted PvP attacks. If you mark yourself as Offensive, then practically nothing changes - you continue to play as you have until now.
Marking yourself as Defensive, however, alters a number of factors. Defensive players cannot be lassoed, critical hits can't be dealt against them, headshots incur the same damage as body shots and attacking them will incur major Hostility penalties. As a Defensive player, you may not lock onto other players, nor can they lock onto you, and any hostile action on your part will automatically switch you to Offensive and incur penalties. This way if you set yourself to Defensive, griefing you will be more trouble than it's worth.
Players can also expect content expansion beyond the odd game mode here and there. Both the Land Of Opportunities mission-chain will continue with more quests focused on Jessica LeClerk, and the Free Roam Missions will also be increased in number.
New random encounters will also be added, such as ambushes or various NPCs in need of help. The Daily Challenges system will be overhauled, removing any challenge that indirectly encouraged griefing in free roam, as well as challenges that require unavailable content. A new weapon returning from Red Dead Redemption is also on its way - keep an eye out for the LeMat Revolver, coming soon.
These features will be implemented is a major Beta Update coming sometime later this spring.