I think Lizard used to hit the cap at it’s peek back when it was at its higher cap so I think we probably always had the players, they were just never willing to join empty servers. I think there have also been a lot of players who weren’t interested in playing on Lizard that are willing to play, or play more, on Leviathan
I assume that’s what’s happening. It may also be growth that would have happened if there was any high pop server with open slots. There may be lots of people every day that download the game, open the launcher and see only empty or full servers, so they just uninstall the game. With Leviathan having had 50-60 pop recently, those players may have decided to play on Leviathan, joining the player base. Unfortunately I don’t have access to the analytics that’d be needed to know what the actual answer is, or how much different things contributed. All I really know is that Leviathan still has much fewer issues than Lizard and higher levels of roleplay.