The alcohol percentage of a still wine will stay the same over its entire lifetime, but winemakers always hope that the flavors and sensations will balance and meld into a nice package over time. The bad news is that in a challenging vintage like 2000 NV Cabernet, my opinion is most wines do not have the components to significantly improve. Some are drinking well now, but few will get a lot better.
Disclaimer: I have not had the 2000 Terra Valentine.
Make Cab, not War.