Just to echo the first answer, but with different source, Dead Man Tell No Tells was/is meant to be the first in a series of final [Jack Sparrow] films, as one trailer states,
"The Final Adventure Begins...." (1:51 Mark)
Wikipedia also confirms that a series of final films were/are intended.
Shortly before the release of On Stranger Tides, it was reported that
Disney was planning to shoot the fifth and the sixth films
back-to-back, although it was later revealed that only the fifth
film was in development. On March 4, 2017, director Joachim Rønning
stated that Dead Men was only the beginning of the final adventure,
implying that it would not be the last film of the franchise and that
a sixth film could be released.
In September 2017, producer Jerry Bruckheimer indicated that another
Pirates of the Caribbean sequel is still possible if Dead Men Tell No
Tales does well in its home release. In October 2017, Kaya Scodelario
said that she was contracted to return for a sixth film. Shortly
after, it was announced that Rønning is being eyed to direct the film.
In addition it should be noted that there are some loose threads, whether it be Davy Jones existence at the end of DMTNT, Angelica being left stranded with the Jack Sparrow voodoo doll at the end of OST, or what ever happened to Philip and Serena, and now that Carina knows the truth about her father, will Captain Barbossa remain dead for good? (It's also why I asked this question).
Contradictions or Something Else?
It also has been reported that some kind of Pirates of the Caribbean Reboot is in the works featuring the Deadpool writers at the helm and with a strong possibility that the theme park character, who has recently been "re-imaged" at Dinsney's Pirates of the Caribbean Theme Park, named Redd, will be the series lead with Jack Sparrow/Johnny Depp being out.
In October 2018, it was reported that Disney is planning on restarting
the franchise with Rhett Reese and Paul Wernick writing the script and
Jerry Bruckheimer returning as producer. It is unknown if the film
will be a complete or soft reboot of the franchise as Disney has not
yet made any official announcements. In December 2018, Walt Disney
Studios President of Production Sean Bailey confirmed that the
character of Jack Sparrow will not be present, explaining, "We want to
bring in a new energy and vitality. I love the [Pirates] movies, but
part of the reason Paul and Rhett are so interesting is that we want
to give it a kick in the pants. And that's what I've tasked them
However, Disney has only confirmed a reboot without Johnny Depp and nothing else.
What's the right mix of original and licensed programming on Disney+?
Many of our core brands are going to be in that service. Some of this
content will have an initial window, like a theatrically released
film, some will be on television first, some will be original for the
service. It will skew naturally from an hours perspective, because of
how much we've invested over the years, toward product that's
non-original, but we're making a lot of original content.
It is my speculation that there is some misinformation that POTC six will be the reboot, as I think the reboot is actually going to be a spin off TV series for Disney+ (Disney's new streaming service), since Bob Iger has mentioned how invested he is in that market and that many other franchise spin offs are already in development there. Pirates of the Caribbean is really Disney's only major franchise that hasn't made an official announcement for a project in development there.
Therefor I think we will also get Pirates of the Caribbean six with Johnny Depp respectively, at some point.