The venerable Igor at Igor's Lab has confirmed the existence of the leaked Radeon RX 5600 XT graphics card and speculates that the card might be launching as early as January 2020 (in time for CES) along with some specifications from his own sources. The RX 5600 XT will be AMD's first 6GB based Navi card and appears to be roughly 3/4ths of a Navi 10 die (more on this below). Igor has been spot on for most of his graphics card leaks and I have no reason to doubt this one either so feel free to dig in!
AMD's Radeon RX 5600XT will allegedly have 1920SPs with a 192-bit bus and 6GB vRAM
The first thing you need to know is that the RX 5600 XT is going to be AMD's first 6GB card in the Navi family. This means that it's going to feature a bus width of 192-bits (and can theoretically support 12GB as well). According to Igor's sources, the easiest way to market for this particular card is to essentially cut the Navi 10 die by 1/4th. Seeing as the Navi 10 die has 2560 SPs to work with, this GPU is going to have 1920SPs. This is going to be coupled with 120 texture units, 48 ROPs and 3MB of L2 cache. This card will deliver roughly 75% of the performance of an RX 5700XT (at the same clock rates).
Igor further reveals that the RX 5500 XT has not been selling well considering its priced a bit too high for its intended target market and the RX 5600 XT could help fulfill some of these gaps. At these specifications, it will help fill the void that EOL-ed Polaris GPUs have left in AMD's lineup and can serve as the step-in replacement for the older Vega 56 variants. Based on 7nm, these cards can clock pretty high and provide quite a decent core count to tflop ratio.
Igor also further discusses the possibility that the company might use hardware strapping to disable cores on existing Navi 10 GPUs and how some AIBs might decide to take matters into their own hands (and lead to the traditional unlocking AMD GPUs into their powerful variants guides that always seem to pop up after using less-reliable methods of disabling the cores). It is expected that the GPUs will launch in the third calendar week of 2020 (which puts this around January 14-2). AIBs like ASUS and Gigabyte are expected to launch with these cards first and we have already seen a listing of GB cards popup on the interwebs.