Does anyone have any idea how they'll do this... Is there a way to convert cryengine to unreal engine?
CryEngine 2 is written in C++
Unreal Engine is written in C++
Most of the logic will be easily moved over (think mechanics of the game, how auction works, movement, pathfinding, etc).
Unreal Engine has a fairly liberal asset import pipeline which would likely make it easy to bring over the game assets (think vehicles, characters, textures, etc).
A game engine basically has a bunch of preset functions which you can use, so things like "press W to run" would be mapped to a function already existing in the game engine, you wouldn't need to reinvent the wheel so to speak. Moving from CryEngine, it might have been a function called something like "moveForward" where in UnrealEngine it might be called "forwardMove" so there will need to be time spent going over the functionality and mechanics of the game to re-map the functionality to what UE5 has to offer.
It's a lot of tedious work but it shouldn't include much new code. A lot of refactoring.
UE5 opens possible doors that CE2 never had access to (or was patchy/needed workarounds to function). Because of this, more features can be added to the game, existing technologies like the networking code can be rewritten or third-party packages can be used to enhance what's already there. UE5 is 100x more popular than CE2 and thus has a lot of developers using the platform, writing plugins, etc. MA could benefit from this by saving $ having someone develop functionality of their own and simply purchase a plugin and tweak it having most of the code already written. Popularity in languages/platforms is big in the development world. Just like in a market, if nobody is participating things move slowly but if there are lots of people participating, it can move quickly (ie: access to more features being written that you didn't have to write but can use).
It's not all about a graphics update. The graphics update is really just a side benefit of using an up-to-date engine. The biggest benefit MA is likely looking at is the ease of use, massive library of tools and pre-written underlying features and overall developer morale being able to use a platform built for today and not for 15 years ago (15 years in tech is like 50 years in mechanics).