Reboot! That's a word that has lost all possible meaning in Hollywood, and it means everything from a sequel to a remake to a premakequel (see Terminator: Genisys). It really means starting over - coming in fresh and redoing it all from the beginning, as in Casino Royale, not as in The Bourne Legacy. And not, from the sound of it, in Pirates of the Caribbean 5.
You may have seen word that Pirates 5 is a 'soft reboot' of some kind, but it clearly isn't, despite what Orlando Bloom says to IGN:
I’m not entirely sure that [I'll be back] just yet, but there are talks. Basically they want to reboot the whole franchise, I think, and do something with me and the relationship with my son… I’m of course Davey Jones now, so I’m down the bottom of the ocean. It might be kind of fun to do something where I’m rumbling round the bottom of the ocean, because I won’t look anything like me. [Gestures to face] Get all gnarly.
Having his character continue from where the third movie left him is essentially the exact opposite of a reboot.
It's very hard for me to care much about the future of this franchise or its continuity, but I do have to say that I liked how Pirates 3 left Bloom's Gummo character and I would like him to stay away. Sure, he got that post-credits scene, but that was his 'one day on land,' Intriguingly, if the series is set in real time the fifth film could be set right before or after that post-credits scene.