It's true. D to E conversions of the MH-65 have stopped. Lack of spares especially magnesium gearbox housings from Airbus.
Back in 2018 USCG were promised 20 years support but in 2020 all the relevant tooling was sold to South Korea for the KAI effort. All new parts will be KAI and not type certified for MH-65 or AS365/155. Aside from all that the majority of MH-65's are around the 30k hour mark so attrition is way above estimates whereas MH-60J and not T models don't suffer such issues.