The character "行" is pronounced "hang" in "银行" and "行业". while it is pronounced "xing" in "不行".
Is there any pronunciation rule that "行" is read "hang" in business terms regarding banks and commercial situations?
The title of the song (and also the cartoon work) is trying to mimic the style of ancient Chinese scripts and verses, whose exact meanings were often vague and mysterious, but could convey a magnificent feeling like "the universe has its ways" or something.
A quote from the classic divination book 《周易》 reads: 天行健，君子以自强不息. 天 means "sky, heaven, universe", 行 could mean "run, walk, work, do", so 行 usually reads "xíng" in 天行...
By the way, "Skywalker" of Star Wars is translated as 天行者 in Chinese.
天行 "the revolution of nature's cycle" (as in《周易》天行健 and《荀子.天論》天行有常):
天: "the heavenly bodies (e.g., stars, planets), the universe, nature"
行 xing2 (a verbal noun): revolution, a recurrent or rhythmical pattern of development (反復循環的發展，e.g., 蛇行：左扭右扭, 左扭右扭...；人行: 左腳右腳，左腳右腳...; 獸行：前腳後腳，前腳後腳...; 車行：輪子轉來轉去，轉來轉去...; ebb and flow)
Connotations of 天行: (1) ever-evolving development (that is, 健 in 天行健), (2) inevitable fate (that is, 常 in 天行有常; 必然之事, e.g., 天下大勢分久必合，合久必分)