I don't know what Desmond Child would bring to the table though. His last successful co-write with the band was "(You Want to) Make a Memory". Before that was prooobably Misunderstood I guess and even that is tough to qualify as a "hit". It's been nothing but album cuts since then. I think you were right the first time, they're too old to have a hit on pop radio and swerving their style into modern would be disastrously transparent.

I suppose they could use DC to lean into the 80's anthem sounds but some of the current songs ain't THAT far away from that style of production, it's just less keyboardy (in my opinion).