This is a great news if it's true! Basically a naval variant of Z-20 will finally complete the modern PLAN ASW network. Anti submarine warfare was always the weak spot for the PLAN until very recently with the new design in 056 corvettes, and 054 frigates, 052C/D DDG equiped with new variable depth sonar etc. And China already got the Y-8Q ASW variant that kinda of equivalent to the U.S P-3 Orion which fills another puzzle.
But the Z-9C currently in service are just not good enough with modern anti-submarine warfare anymore with it's light weight and short legged range which handicap the PLAN's ASW strength. A naval variant of Z-20 for PLAN will fix the weak link of the ASW network and turning what was a weakness of the PLAN into strength combining with other modernizations of the navy. It will be huge leap of ASW capability when it happen.