Thank you. Yes, using pattern matching to declare a variable with the empty property pattern is an effective way to combine the Is Not Null check with a variable definition that can then be used inside of the if-statement.
Pattern matching is an area that has been receiving many enhancements in the C# language over the last few versions and each of the various patterns can be combined to produce very complicated checks (including for null). You can see more of them here: https://learn.microsoft.com/dotnet/csharp/fundamentals/functional/pattern-matching.

if(Foo() is {} foo){
// do something with “foo” here
}