FormRevealMode.Inherit always resolves to Classic instead of inheriting the expected reveal mode #15139

.NET version

.NET 11 RC2 build

Did it work in .NET Framework?

Not tested/verified

Did it work in any of the earlier releases of .NET Core or .NET 5+?

.NET 11 new API involved

Issue description

When setting a Form's FormRevealMode property to Inherit, the effective value always appears to resolve to Classic.
When FormRevealMode is changed to Inherit:
• Classic → Inherit: the Form continues to behave as Classic.
• Deferred → Inherit: the Form also ends up behaving as Classic.
In both cases, Inherit effectively resolves to Classic.

The behavior is consistent between the Visual Studio Properties window and WinForms runtime.

Steps to reproduce

1. Create a WinForms project.
2. Set the Form's FormRevealMode to Classic.
3. Change FormRevealMode to Inherit.
4. Observe the resulting behavior/value.
5. Repeat the test with the Form initially set to Deferred, then change it to Inherit.