I am always wary when someone wants to change the language of something, or say "this is the word that must be used!"...in my humble opinion, there is often a "control freak" mindset behind this.
*mini-rant about language police - only bother reading if bored*
I just am one of those difficult people who always ask questions, and wonder why? "Question everything" is a good motto, because it makes people who want to control things uncomfortable. Language is really powerful, as the main communication conduit between human beings, and so whenever I hear there is a trend to change a word or whatever, it just makes me suspicious.
So I enjoy using the "forbidden words" on purpose, just because I can, lol. Words I still use regularly, even though they were deemed "incorrect" now, by the "cultural powers that be" -- "mankind" "master bedroom" "policemen" "policewoman" "actress" "actor" "disabled" "homeless" (believe it or not, among this censorious wing, they want to use the word "houseless" to replace the standard word used - "homeless" - its very bizarre, but they think this is a necessary change....my reaction is wtf? Why?? -- yikes!)
*end of mini-rant*
Anyway, use whatever word you like best, lol - my 2 cents. "Diablo clone" is fine, "Diablo-like" is fine, "Action RPG" is fine,
they are all fine words to use.