Update: I've reached out to GIGABYTE/AORUS which have confirmed with TweakTown that they are indeed making custom Radeon RX Vega graphics cards, there's just "no news on the horizon" yet.
If you've been waiting on GIGABYTE or MSI's custom Radeon RX Vega graphics cards, you won't have to wait any longer - or wait at all, because the companies aren't working on them according to fresh rumors.
AMD has been reportedly having troubles getting Vega GPU production in large numbers, which is something I exclusively reported earlier this year when I said AMD would have less than 16,000 available post-launch. Here we are, post-launch, with no official sales numbers to go by.
ASUS is the only one with a custom STRIX Vega 64, something that is on its way to me as we speak. VideoCardz reports that the "competition believes that ASUS card was just a PR stunt with questionable value as it provides minimal improvements over the reference design". We'll see when it arrives.
As for what GIGABYTE and MSI are doing, the two companies are working on custom GTX 1070 Ti graphics cards which should arrive late next month.