I came back after 4/5 years. They could come back too. All they need is to turn 30, have a mid-life crisis and have an inner battle with themselves over feeling old. "NO. I'M NOT OLD. I PLAY GAMES. LOOK. RUNESCAPINGGG."
I actually logged in to find a similar situation. I messaged one of my friends who I had played with way back in the day and told him his username was available to use. I threatened to take it unless he gave it a go and BOOM there he is; mining coal like a nub. Got him hooked again