I doubt projects like this would help. For big developers, 99.99% of the time they are already riding on existing codebases (even when they call it by different names for marketing reasons) - the last two AAA games i worked at have codebases more than a decade old, one actually two decades old. While technically they could add rust as an extra language, in practice this wont happen both because the vast majority of game developers are conservative in terms of languages but also because it creates extra barriers (most people who write C++ code in games barely know C++ - the wizkids that everyone has in mind when hearing about high octane game engines are a tiny minority compared to
everyone else who touches a game's codebase) which make it harder to hire new people (unlike other disciplines in gamedev, decent programmers aren't as easy to find). Also everyone hates how slow C++ is to compile and last time i checked rust is even worse.
For smaller developers projects like this still wont help drive adoption since smaller developers have the freedom to decide on their own what language they'd use (assuming they aren't already using an existing codebase, some of the stuff above also apply to smaller developers) and they'd already be using rust if they thought it'd help. In general i believe that developers who have enough knowledge to make their own engine in other languages and be able to make their engine in rust, would be able to tell if rust is a good choice or not.
Or to put it in another way, i doubt projects like this will help drive adoption for rust among game developers because the developers have either already decided what language to use (be it rust or something else) or are not in a position to decide what language to use.
(yeah sure, there might be an exception or two out there, but there are hundreds -if not thousands- of engines... after all Remedy, a AAA studio, used D in their engine yet you do not see much of an uptake of D among game developers even though technically D would be easier to grok by C++ programmers, integrate with existing engines with its C++ interop and even provides features like compile time code evaluation and generation for features that i've seen C++ projects use overcompilated macros and external build time generators that rely on brittle code comments to work)