We would not be able to rip out floating points out of the egine even if we had source code access. Maths, graphics and physics libraries for games and even C++ compilers all usually are written explicitely for floating point numbers instead of simulating it with fixed point arithmetic. Switching away from floating point, if at all possible, would probably result in an engine too slow to be usable.
And for little reason, becasue the imprecision of floating point is not really the problem here. A problem only appears if the imprecision varies from machine to machine. If you use the exact same hardware/software, you will still have floating pint imprecision, but it will be the exact same imprecision on every machine, so the game will not desync.
However, when hardware is emulated you often run into problems where the emulation has to do things slightly different than real hardware for performance reasons.
Anyway that doesn't matter much because we still need engine source to find problems with the strictness of FP operations.