What is the "Gold Master" plan (shown by MetaGrid Pro 1.7.2 instead of "Unlimited Lifetime")?

It took a while until the more recent versions of MetaGrid Pro finally correctly indicated that I had purchased the Unlimited Lifetime plan. MetaGrid Pro 1.7.2 now says that I am on the “Gold Master” plan. What even is that? Is this supposed to be displayed, or is it a new bug? When I go into “Explore Plans”, it still correctly indicates that I am already subscribed to the Unlimited Lifetime plan.