The reports of the Notre Dame's defensive demise have been greatly exaggerated.
Freeman is familiar with Navy, and will have a plan in place to stop the frustrating triple option. The tackling will be sound by virtue of Navy's ball carriers not having forcefields around their lower body like Sam Howell seemed to have. We might even see some young faces help out that we haven't seen much of yet since we're getting to the 'four game redshirt' time where reinforcements can help out without burning eligibility. Fresh bodies and legs can help when you're taking cut blocks on every snap.
On the flip side, I think ND's offensive skill players are going to give Navy fits, the same way they did in '19. Tommy will scheme to get any of the WR's matched up against some poor schmuck playing LB for Navy, and that guy will get toasted, and then a different guy will get toasted on the next drive... we just need Styles to catch the deep ball when it happens.
I think he will catch the deep ball (or maybe even two), and I think ND rolls, 45-14.