Det antas vara tillbaka inuti honom
Som du noterar:
Davy Jones put a curse on his heart, making sure that anyone who destroys the heart must remove their own heart, and preferably keep in in a box.
Så snart förbannelsen lyfts, finns det ingen anledning för Will att hålla sitt hjärta i en låda.
BlueMoon93 sammanfattar detta för oss på [movies.se]
Once the trident was broken, the curse was broken. He
- was able to come back to land
- lost the barnacles and sea-elements covering his body
- has his heart beating back inside him (otherwise he would just die)
- no longer commands the Flying Dutchman
- no longer survives underwater
Despite this not being directly showed in the movie, it seems like a reasonable interpretation. He is just a regular man now, and doesn't have a hollow chest (as he is no longer cursed).
Som en slutlig notering, kom ihåg att POTC tycker om att spela snabbt och löst med kontinuitet ( hosta döda män berättar inga talar hosta ), så hjärtat går att vara exakt där Disney behöver det för att vara nästa gång de behöver det, oavsett huruvida det strider mot tidigare fakta.