In the early days of roleplaying it was relatively easy. Gaming was new. Being a gamer was part of something quite original and exciting. *Being* a gamer was enough to be part of player and community development. In a gamist sense, the old AD&D convention system worked well too. There were challenges, goal-orientated objectives etc. It was rather like a MMORPG under one roof, minus the 'o' (online) part, complete with prizes! (history link: http://php.iupui.edu/~wrporter/Genconhistory.html)
RuneQuest had a different method; with an extraordinary gameworld being a RuneQuest player ('gateway' games notwithstanding) meant contributing to the fantastic world and story of Glorantha. Players had their characters immersed in a particular point in Glorantha's history and such a large portion of the world was only slightly sketched out that there were numerous opportunities to "build the world". The integrated nature of Glorantha meant that it attacted a lot more player input than say, AD&D's World of Greyhawk; and rules-wise, especially in melee combat, the influence of SCA involvement meant that perhaps it is not unfair to describe player involvement as 'simulationist'.
White Wolf's motley collection of conspiratorial and supernatural games in the (old) World of Darkness publications from 1991 to 2003 (Vampire, Werewolf, Mage, Wraith, Changeling, Hunter, Demon, Mummy, Kindred of the East and Orpheus) included significant discrepancies and cosmological contradictions. This was "resolved" by the "Time of Judgement" scenarios which ended the game. I'm not sure how to describe this, but it sure ain't narrativism (even if it had a narrative of sorts).
Now for a historical fantasy game, would it all be plausible to encourage player involvement and community development through an "Alternate History Project"? One that not only encourages players to learn about the history and mythology of a setting which they conduct their games in, but also one which allows their resolutions to be reviewed?