There's exploration of integrating hypersonics with antiship strike capability on subs. But the TLDR is until PLA's massive A2D2 expansion to 1IC and beyond (15

There's exploration of integrating hypersonics with antiship strike capability on subs. But the TLDR is until PLA's massive A2D2 expansion to 1IC and beyond (1500km+), there aren't any adversaries that can prevent carrier groups from operating permissively - USN CSG airwing had standoff advantage against everyone. Hence (IMO) little reason (without consider technical stuff like extending kill chain to underwater - subs would need to get target queuing from above water sensors) to integrate SAMs/ASMs into subs, because as expensive as carriers are, subs are even more expensive per unit of fire/tube/vls. Extrapolate from Zumwalt hypersonic retrofit projections current 80 cells for TLAM (tomahawks) whittles down to ~12 CGHBs (common hypersonic glide bodies) to a SSN (~20 shots) and all of a sudden it costs 100-200m+ per shot on a 2-4B Ohio class. Extrapolate to SSNX @6-8B and cost ratio per shot gets even more ridiculous.