Earlier this year Fairy Tail fans were given the last manga chapter of the series, which marks the end of the Fairy Tail franchise, as the anime starts to produce the last ac. The announcement sanded many Fairy Tail fans, however, it turns out that they were quite lucky, as this should have happened much sooner.
According to an interview with the creator of Fairy Tail, Hiro Mashima at Comic-Con New York, the man behind the series was meant to finish up Fairy Tail much sooner. In an interview with Mashima, he stated that the only reason the series continued for so long was due to the enormous following and that he originally intended to wrap up the franchise years ago.
.@hiro_mashima originally planned Fairy Tail to be 10 volumes, but thanks to the love from fans, it was developed into a longer series.— Kodansha @NYCC #2109 (@KodanshaUSA) October 5, 2017
However, the series continued and only recently ended but Fairy Tail fans have been left with some hope about Natsu possibly returning, with Mashima stating that it's possible. With that said, the reason it is possible for the series to continue in the future is because of the way Mashima ended the franchise, he left it open for anyone else to take it on. Therefore, it's possible that in the future someone might want to take up Mashima's work, however, at the same time, it's possible that it won't happen as well.
You can check out Kodansha Comics' summary of Fairy Tail below:
"Cute girl wizard Lucy wants to join the Fairy Tail, a club for the most powerful wizards. But instead, her ambitions land her in the clutches of a gang of unsavory pirates led by a devious magician. Her only hope is Natsu, a strange boy she happens to meet on her travels. Natsu's not your typical hero—he gets motion sickness, eats like a pig, and his best friend is a talking cat. With friends like this, is Lucy better off with her enemies?"