Your theory is that entire communities of explorers would leave because after they leave the game for a year (or more) their discoveries would reset?Mhm. So on one scale, we have some vague and uncertain community benefits. On the other, we have the certainty of losing players and/or communities, with only the quantity being uncertain. Plus the uncertain costs of implementing and running this.
Well, I'm fairly certain the scales aren't balanced.
You know that sounds a bit silly.
Don't tell these people the game will be shut down one day because, based upon your premise, they'd all quit if they knew that.