In the Settings menu for StarCraft II, my RX 5600 XT shows up as “AMD RADV NAVI10 (ACO)”. Is there a way to fix this? Or might this be fixed with an update to something?
That shouldn’t be a problem, it’s how your GPU is identified. That’s your Vulkan info. It might make the game default to “low” settings on first run if it doesn’t get information it likes. but just set what you want. As far as I know, no game actually gets a real hardware string for me.
It really depends on what method a game uses, but it’s usually going to be bogus in a Wine environment. Games that follow the directx interface might identify it as whatever it gets from the dll chain (e.g. aticfg dlls). In that case mine identifies as RX 480 (umm, it’s actually RX 570) driver version 9.17.10 (the version that the generated dll has) with -2 Gb of VRAM. Bollocks 
Or it will identify like AMD RADV Polaris10 (ACO) which is at least correct.
It is what it is, unless there’s a problem. Are you having one? Chances are that is a red herring, if so. Things you spend time investigating, but have nothing to do with the problem. I just went through that recently myself, suspecting driver string causing directx initialization problem but no.
Last week I had a similar problem with RDR2 where my Nvidia card was identified as an AMD card and asked me to upgrade my drivers. After confirming I had the latest Nvidia drivers I was confused as to how this could be. After much fluffing around I upgraded Kubuntu 20.04 to 20.10 and the card was then correctly identified. My takeaway from this is that the new software that allows us to play games on Linux needs everything to be up to date, especially Ubuntu kernels.