They're not looking for your solo to be a perfect copy of the studio recording, but they do want to see all of the fundamentals that make up the solo. I think the reason they choose Beat It by MJ is because of all the techniques the solo uses (tapping, legato, bends, tremolo picking etc), so they can see if you can do it all.
I am by no means a "fast" guitarist, so I adapted some parts which still sounded very similar to the recording, but made it easier for me to get my fingers around. I wouldn't advise that you adapt the solo too much or improvise it, but you can change small parts to suite you, as long as they sound similar to the original, like I did.
When I found out I had to play beat it for my audition piece, I was definitely worrying as it is something very different to what I'd usually play, but I made sure to spend 30 minutes to an hour everyday for a month absolutely nailing it before I sent it off to them.
You're definitely in a good spot at the moment, you've still got lots of time to practice to make sure you can get it down.
I really hope this helps, and if you need any more guidance or advice then we can always talk over Instagram about it to make communication easier (@osmith_music).
Best of luck to you!