AI is nowhere near able to take a hardware ROM and convert to software emulation or even create valid blueprint of it. Just like anything that came before it, it's a tool and good at some things, n0t at others. Even with AI, all of the bugs, misunderstood bytes and broken dsp in mame are still there. The only thing I've used AI for was to document mame's code to understand what needs to be coded in dsp and the parameters for some of the midi dispatcher and build the plugineditor UI because I hate coding UI. I also used it to write a quick script to brute force me about 1000 dpcm decoder variations to finally work out what mame doesn't emulate correctly and has DC offset issues too.

As for XG being dead, the main issue is now even midi drivers for say my MU2000 no longer work on Windows and yamaha removed them, so even hardware is becoming less desirable to use if you want specific XG sounds. That's what most people love about XG, is that many sounds are so familiar they want something convenient. So far no rompler of samples really sounds correct or better than an MU2000.

Well then there's your route: update the MIDI drivers for modern Windows, even Linux. Don't need to understand Yamaha's methods to do that, just a decompiler.

What happens with AI is people contribute complete projects to it with notes. The AI alone does not do the job... there is a filter which identifies high value code and recommends it to the analysis teams for inspection and curation. In the case of the MAME project the filter would flag the code by noticing the name "Yamaha" and the team would extract the DSP bits and specially train the AI on it make it more competitive with real engineers. Because it's incomplete they might not prioritize the project immediately, but if someone did a decompilation and put it on Github somewhere then they'd use it to fill in the gaps in the MAME driver...

As I said in the beginning. Th MU Hardware has many limitations and SYXG50 is cracked and decrypted with many restrictions because it was never designed for 3rd party hosts and most hosts don't' support sysex anymore to the VST layer and XG was obviously extended beyond GM. Software opens up to improve not only sonic quality but many other things. MPE, oversampling, advanced filters, improved imaging, more advanced interaction with host modulation, audiorate modulation etc.

As for AI, it already knows everything about a Yamaha swp30, there's nothing to teach it with. It wrote a script to geneerate 1000s of decoded dpcm, I worked out what mame missed, AI learned nothing new, not even what dpcm mode mame missed.