It would be AI by the standards of A*, maze solvers, and similar. It isn't ML and doesn't isn't related to that branch of AI.

Should graph search be considered AI? This gets us to the root of the issue, which is how do we consider something AI or not and to what extent has that definition changed as some problems have become trivial or commonplace. Machine learning is a bit easier since you can create much strong classifications around the need to teach, to feed it data with expected results, before it is useful to get a response (or otherwise give it a way to evaluate data it generates and then feeds itself). However there are a number of techniques that predate ML, or at least having fast enough computers to have worthwhile success at ML, and thus we are left with determining some way to objectively classify those as either AI or not.

It is technically not AI, but it used to be called AI.

AI today is the study of optimizing NP problems through a series of educated guesses.

> Has the definition of "AI" changed?

https://en.wikipedia.org/wiki/AI_effect

It would seem that the AI goalposts are always being moved.

They weren't saying the fill tool was an early form of what we think of as an "AI algorithm" today, but that the leading edge of machine intelligence / intuitive capability has changed, and it will continue to change.

Also you can probably implement fill with a graph search algorithm.