Nope. 3DO / CagEnt's MX technology, bought by Microsoft, never got used in the original Xbox that launched -- That was entirely an Nvidia + Intel chipset. It may have been the WebTV team's proposal for a console, which was ultimately rejected, that would use MX or GigaPixel's graphics chip.
Here's an article that goes over most of what I posted originally from Next Generation:
https://dromble.wordpress.com/2014/01/07/dolphin-tale-story-of-gamecube/
Now, It has been said that ArtX had obviously seen what 3DO / CagEnt had done with the MX technology, using graphics RAM built directly onto the graphics chip, and while ArtX probably didn't copy it, they likely decided to go that same route with their own design (Flipper) also using embedded (MoSys) memory. Also, instead of using MIPS CPU, as Nintendo originally wanted for the MX graphics tech (it was coupled with PowerPC) ArtX probably helped Nintendo decide to choose IBM as their CPU partner, and get PowerPC architecture in the new console (Dolphin) same as what 3DO chose for M2 and MX.
Slightly confusing but interesting at the same time.
There are some basic similarities between M2, MX and Dolphin / GameCube. The MX technology was never seen directly though, whereas M2 was, an existed in 5 Konami arcade games and numerous demos. But It is fair to say the GameCube represented a big leap over the MX technology in terms of sheer polygon performance, just as the MX technology was a leap over the M2.