There's a couple different ways to look at this. From a charitable point of view to ubisoft, they do not advertise support for Linux. Instead they openly state it's a window's only game. So when a third party (i.e. Valve) makes shim that grants linux functionality, it's not really on Ubisoft to maintain that.

However, from a consumer perspective, this is incredibly frustrating. The average person does not think of "linux vs. windows". They just bought the steam deck and when they bought For Honor it was sold on that "platform". Again, it's hard to blame Ubisoft for this conundrum since they were never necessarily trying to be steam deck compliant to begin with, but it definitely feels wrong to take the game away from a player in this perspective.

All that being said, historically across many games such as Rust, many are quick to blame linux for cheating, but pragmatically banning linux has yet to measurably reduce the amount of cheating that players report experiencing, so I don't agree with the decision at all. It's a footgun disguised as a band aid

> So when a third party (i.e. Valve) makes shim that grants linux functionality, it's not really on Ubisoft to maintain that.

I agree that it's not on them to maintain it, but that's different from intentionally breaking it.