redlink is a generic wiki term and means that the word is linked, but that the article the link points to does not yet exist. It is displayed in a color different from normal, "active", links to encourage others to go create that page so that the wiki grows.
The actual color of a redlink will vary across the Wikibase as many of the game sites modify the stylesheet to change the default colors for "active" (normally blue) links and redlinks.
Some think that redlinks are "wrong" or a sign that the original page editor was lazy, but this is patently wrong. Redlinks are actually a sign of health in a wiki. They are a sign of growth and an open invitation to the reader to contribute.
There is an old joke, often referred to as "Murphy's 3rd Law of Computer Programming" that says "Any program, once bug-free, is obsolete." The corollary to this is "All worthwhile programs have bugs." Why? Because any time changes are made to a program bugs are introduced. Only over time are they identified, run down, and fixed. Any program that has active users generates modification requests, and the more used it is the more requests it generates. When it stops doing that, and thereby is no longer being changed so that it has the chance to become bug-free, this is a sign that no one is using it anymore.
Similarly, a Wiki with no redlinks is static, stagnant, dying.