This depends on what kind of unfalsifiability you want. There are at least four kinds.
unfalsifiable with current resources (Russell’s teapot)
unfalsifiable because of moving goalposts
unfalsifiable because the terms are incoherent or undefined (“not even wrong”)
unfalsifiable in principle
No empirical claim is unfalsifiable in principle (i.e. without resource limitations, moving goalposts, or logical incoherency). Claims that involve violations of physical law come the closest, but require us to assume 100% confidence in the law itself. For a non-empirical claim to be unfalsifiable, empirical consequences of the claim have to be impossible, which ultimately requires you to eliminate them by definition. I think you’re trying to find an example of the fourth meaning when most people who talk about unfalsifiability are thinking about one of the others.
This depends on what kind of unfalsifiability you want. There are at least four kinds.
unfalsifiable with current resources (Russell’s teapot)
unfalsifiable because of moving goalposts
unfalsifiable because the terms are incoherent or undefined (“not even wrong”)
unfalsifiable in principle
No empirical claim is unfalsifiable in principle (i.e. without resource limitations, moving goalposts, or logical incoherency). Claims that involve violations of physical law come the closest, but require us to assume 100% confidence in the law itself. For a non-empirical claim to be unfalsifiable, empirical consequences of the claim have to be impossible, which ultimately requires you to eliminate them by definition. I think you’re trying to find an example of the fourth meaning when most people who talk about unfalsifiability are thinking about one of the others.