As long as it sounds great then I have no idea why Gigabyte did that. Looking at the specs, the new models are barely different. The only thing which seems interesting is that they claim that new mobos work with DDR5-8000+. This is from their website:
"AORUS is offering a tested and proven platform that ensures proper compatibility with profiles up to 8000MHz and beyond. All users need to do to attain this performance boost is to ensure that their memory module is XMP capable and that the XMP function is activated and enabled on their AORUS motherboard."
I only wonder how much truth is in that as most of their motherboards, even the highest models, have problems running at DDR5-6000. The Z690I Ultra Plus has 6200 (OC) in general specs which is quite low, but there is no QVL yet.
Edit:
One of the reasons why Gigabyte released Lite/Plus versions is that the previous ITX Ultra mobos have a design flaw and are causing stability issues with PCIe 4.0 cards. It can't be fixed with a BIOS update or anything like that so Gigabyte will replace all older motherboards with the new versions via the RMA process. For the first time I see that Gigabyte is replacing motherboards, so good for them ... and for all who purchased previous Z690 ITX Ultra models.
Edit2:
Gigabyte corrected the product page. Now is DDR5-6400 and on the QVL is max 6400 too. I don't know from where they got that DDR5-8000+ but it was too good to be true
