You are an older MMO. You don’t look sexy anymore.
Your players think a graphical upgrade would help you recruit new players. They tell you how embarrassed they are to be seen playing you and how easily they could convince all their friends to play too if you just looked a little nicer.
Your bosses think a new graphics engine should form the core of your next expansion. They tell you how important looks are to getting new players and how much reviewers like shiny graphics.
Your team members think a graphical upgrade, especially a new graphics engine, would be great. You’d get new players, maybe some more marketing money, and it wouldn’t even affect content creation all that much because graphics is all code.
Let me give you some advice: Don’t do it!
You will never be the prettiest. That boat has sailed.
Your players are fooling themselves. If they haven’t convinced their friends to give you a try based on their stirring recitations of your game systems, some shiny art isn’t going to help.
(And it’s not like they’re going to quit out of embarrassment. When they do quit, it will be because they need a break from your gameplay.)
Your bosses are fooling themselves. You’re an older MMO. You will never be an impulse buy for a new player looking for something shiny. You’ll be lucky to get a cursory look and half a column from major reviewers.
(Online reviews will be happy to dissect the intricacies of your game systems at length. If they mention your graphics at all it will probably be in the context of how they really aren’t that bad. Really!)
Your team members are fooling themselves. Graphical upgrades will drain time from new features and game systems, from new art, and from QA. And all of those things will have a fundamental impact on the ability to add more content.
Worse, a graphical upgrade may well slow down your art pipeline – and therefore your content development – in the future.
No matter what you do, be very, very careful about affecting your system requirements. Raising system requirements on a live game doesn’t just throw away existing players – it throws them away with extreme prejudice.