It's default legal talk. Chances are most makers have these sorts of statements somewhere.
I agree the main purpose is for production evolution. For example, if KAI patents a new joint system, or washer design, or heat treatment of the titanium, or updated engraving, they may want to use it on existing knives as a form of constant quality improvement so they continue to make a better product as they go.
Chris Reeve has done this many times over the years with the Sebenza and Umnumzaan after getting usage data that can only be obtained from long-term, real-world usage. Benchmade a few years ago changed many of their 154CM knives to S30V or D2. Spyderco has updated the Delica and Endura 4 times through successive generational advancements.
ZT did this a few years ago with the 0550 in which they released a second generation 0550 to improve upon the knife by addressing the top complaints people had regarding a few minor details (such as the pocket clip), which arguably made a great knife even greater.
With a company like Microtech, they tend to change steels like you and I change socks. I am sure they have some disclaimer somewhere as what steels they use are absolutely unpredictable and not always for the better. With KAI and most makers tho, major changes like this aren't super common.