My opinion is that this is a fake, much as I assume the Earl Weaver interview is.
It appears to be legit.
Wow!
This reminded me of the Buddy Rich tirades. Not about baseball, of course, but worth a listen. This site has audio and transcripts. Have fun.
Historical note; the 1983 Cubs finished the season 71-91, 19 games out of first place. Elia was fired in August.
The next year, with Jim Frey managing, they won the division.
Oh, it’s not a fake.
My all-time favorite baseball tirade is the one my husband had in the car on the way home from the Cubs game last night. But I didn’t record it and I couldn’t possibly do it justice to try to recreate it here. 
Tommy Lasorda’s rant on Dave Kingman is also pretty good.
To wit:
“What’s my opinion of Kingman’s performance!? What the fuck do you think is my opinion of it? I think it was FUCKING HORSESHIT. Put that in, I don’t fucking care. Opinion of his performance!!? Jesus Christ, he beat us with three fucking home runs! What the fuck do you mean, ‘What is my opinion of his performance?’ How could you ask me a question like that, ‘What is my opinion of his performance?’ Shit, he hit three home runs! Fuck. I’m fucking pissed off to lose the fucking game. And you ask me my opinion of his performance! Shit. That’s a tough question to ask me, isn’t it? ‘What is my opinion of his performance?’”