Fedora ships with a newer kernel at the moment than Ubuntu/Mint/Debian. However you can backport the kernel to Ubuntu LTS.
Linux isn't a priority for any vendor right now, so you need to do your due diligence at the component level similar to people making Hackintosh PCs. For example, proprietary custom Realtek LAN or Killer LAN is something you want to avoid. You would also want to avoid overly complex USB hub situations and any PCIE splitting that involves a obscure PLX chip. Anything you need a special driver for in Windows is something that is a liability to break in Linux and the more bleeding edge it is the less likely it is to supported out of the box.
Having 2 SuperIO chips to provide added sensors and fan headers is sometimes problematic for monitoring , but there are workarounds for it since the two main companies are ITE and Nuvoton.
The dev groeck gave up supporting IT87 for Linux (see
https://www.phoronix.com/scan.php?page=news_item&px=IT87-Linux-Driver-Axing) but it's mirrored around the Internet such as here
https://github.com/a1wong/it87 and
https://github.com/rpavlik/it87
k10temp works regardless (the CPU temp).
By the way this is one reason to set fan curved in BIOs and to have good power delivery. Monitoring in Linux isn't always on point other than CPU+GPU temp.
(One of the nice things about the Aorus RGB is once you turn it off in BIOs it's off even in Linux (or if you make it a pattern or a static color it keeps that but I don't bother since it's extra glare if you put your PC atop a desk and extra power use). I haven't seen much in terms of people developing for the RGB SDK found here
https://www.gigabyte.com/mb/rgb/sdk)
I don't think Fedora is technically suited for gaming, Ubuntu 18.04LTS is more suited for consumer-facing applications such as gaming. In fact Steam play apps usually recommend Ubuntu 18.04 LTS and Navi's
AMD drivers officially support Ubuntu 18.04 LTS only. Typically when you see the pro variant pushed out (Radeon Pro / Quadro / EPYC / Threadripper / Ryzen Pro / Xeon) the product is truly out-of-the-box ready for the public and validated for stable use.
edit: also pay attention to IOMMU grouping if you are using GPU passthrough. Level1techs usually covers this well :
https://level1techs.com/article/ryzen-3000-radeon-5700-xt-ready-linux
More on topic :
the X570 Master ICs
Intel 1G LAN
Realtek ALC1220-VB for audio , ESS ES9018K2M DAC
P13EQX ReDriver for USB 3.1 gen 2
Realtek RTS5441 for USB 3.1 gen 2 type C
P13EQX16 ReDriver for PCIE 4.0
IDT6V4 for BCLK modification
IT8688E SuperIO (also used on Z390 Aorus Master)
IT8795E SuperIO (Same as X399 Gaming 7 , X299 Gaming 7)
https://news.xfastest.com/review/review-03/66825/gigabyte-x570-aorus-master/