I know everyone is posting their "here's what I would have done" fixes, but if you'll indulge me in mine since I took the time to animate a stupid demo:
A single disc has been done a ton of times, there's nothing unique about it. So as long as JJP is going to 'already been done' I would have switched to magnets instead. Same idea, random ball action, put in 3 or whatever, get it bouncing around a bit, just like the original disc transitions. Might work better than the single disc, might be around the same, can't imagine it would be all that worse. We've seen it before (Addams etc), it works.
Keep the exact same art that people already liked, with the 3 concentric discs, but — this the key — keep the lit inserts. It sucks to lose the inserts. Who wants to give up playfield lights? They look cool, they were interactive and one of the features. Keep them.
Then what you do is while the magnets are active, you light the inserts quickly one at a time in a circle around each disc, so you get a 'virtual spin' effect. Then they can still stop and land on something, just won't line up the same. Keep the new animation on the backglass LCD,it looks really nice, and is what anyone watching you play will see. You can read it off the playfield by inserts, or look up for the show if you care to see everything line up.
Magnets aren't anything new, it's true, but neither is the single disc, so seems equal enough to me, and you still get the inserts, the spinning effect could still look cool, and it would keep the original spirit of the 3 ring map still. And if you've never owned a magnet in playfield game it's a fun thing to have, and it's fun for guests to see the ball suddenly change course 'magically'.
I was never gonna pay for this game no matter what, but if I was a buyer I think I'd be more okay with that switch. It's not as cool, granted, but it feels less like taking something away. I'd take the virtual spin with magnets over discs that were breaking making the game unplayable, or that were jerky or didn't work great and were annoying.
My two cents. It's not a huge project to engineer some magnets, they already have the inserts. Not trying to handwave changing anything as easy, but it's a a well explored topic by now, not need to invent new mechs or mess with motors etc. That's what I'd do at least.
Here's a quick gif of the idea: