There is too much in max, that needs fixing, to convert it into modern platform.
I doubt it's possible. It's a high level operation software with obsolete maxscript.
There are attempts to make max better, like max creation graph based on external language and data channel. But it will face structural limits.
MCG misses good tutorials and real time scene control.
Also people wants node based management system instead of schematic view, wire manager, parameter collector, etc.
Faster tools to streamline production in certain areas, dynamic booleans, baking, better uv and counting.
In today's state max is nice app for a very primitive animation, but mostly for rendering static scenes.
But even in static scenes it's missing approximate viewport feedback (mostly lighting) for photorealistic renders and native tools, like scatters, ids management, mass parameters editing, randomizes etc. VR and 4k will shift this area to game engines.
So, it's a an obsolete single threaded platform with a bunch of plugs over it, which has different interfaces and ideology.
May be it's a reason why there is no new features: it is too hard to code them this platform.
My opinion: may be it's easier to create a new platform with external plugs, instead of rewriting old one. Not just because computers will have more cores, but also because industry standards applies faster adaptation for new requirements and cross software pipelines.