Soul Calibur VI fails to launch as of its newest patch

[motmontheinternet]

Compatibility Report

• Name of the game with compatibility issues: Soul Calibur VI
• Steam AppID of the game: 544750

System Information

• GPU: Radeon Vega 56
• Driver/LLVM version: Mesa 20.0.8
• Kernel version: 5.7.1
• Link to full system information report as Gist: https://gist.github.com/motmontheinternet/58f6e258c1998809feb314046f4f7f8f
• Proton version: 5.0-9 (also tried earlier stable builds)

I confirm:

• [ X] that I haven't found an existing compatibility report for this game.
• [ X] that I have checked whether there are updates for my system available.

Can't upload error log because it's 1.5 GB in size.

Symptoms

SC6 released an update a few hours ago that seems to have broken Linux compatibility, apparently this is happening to multiple people. This thread linked indicates that the issue might be that the patch updated Denuvo and now the game won't run.
https://steamcommunity.com/app/544750/discussions/0/2953754543764162810/

[kisak-valve]

Hello @motmontheinternet, we're using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to #1780 (comment).