Yes, they have a finite lifespan. Ski boot molds are made of aluminum rather than steel. This means they wear out quicker but it is what allows them to be modified should any changes need to be made, which is a huge reason we make them out of aluminum in the first place. Every injection cycle causes a minute amount of wear & tear to a mold and after x-thousand injections they will need to be repaired, resurfaced, etc. Eventually they just die out. Boots that have low production quantities (like World Cup boots) will last longer than boots that have very high production quantities (like Hawx Prime).
We amortize mold costs over 4 years, so we generally make a new model every 5th year (could be faster, could be longer depending on market needs). We could keep them for longer, but models usually become rather dated by then anyway and we'll need to do an update in order to stay relevant against the other brands.