My old mavics- er, the 719s I think, might have been the 721s- cracked to buggery around the spoke holes. I stopped using them once i noticed but god knows how long they’d been like that under the protective mud coating.
One thing is, swapping the rim on an intact wheel is pretty straightforward, But if the rim breaks, it’ll most likely demolish the spokes too. So that could be a false economy but tbh it’s just guesswork. I know my bikes are possessed by malignant imps so if I was to ride on a cracked wheel, it’d break at the most irritating time, guaranteed but if your bike isn’t evil then maybe carry on