C# inheritance and the "this" keyword

Yes, that is correct. However, to correct your terminology:

• There is no "default constructor" except possibly the parameterless constructor, which doesn't appear to exist on this class.
• This has nothing whatsoever to do with inheritance. This technique is actually called constructor chaining.

This is correct and the technique is called constructor chaining. In this scenario the this call can be loosely visualized as saying

Run the specified constructor before the current constructor

They both run against the same object instance so changes in the called on are visible in the original.