What happened to Heath?

Question

Heath is an inhabitant of Alexandria and is one of the community's supply runner. We see him regularly in Season 6 when he goes out of the community for supply with Glenn or Tara.

In the 12th episode of Season 6 Not tomorrow yet, Heath and Tara are on a long supply run when they are overwhelmed by walkers on a bridge. Their fate is unknown until Season 7 where we learn that Tara fell off the bridge and was rescued by the Ocean Side community.

Heath's fate is unclear. After leaving Ocean Side, Tara goes back to the bridge and Heath is nowhere to be seen. The character never appears in the series afterwards, though it would have been a useful asset in the war with the Saviors.

Out-of-universe, we know that Corey Hawkins, the actor portraying Heath, was chosen to be the protagonist of the short-lived 24: Legacy. But the show only lasted one season and he never returned.

The Walking Dead Wikia claims that Heath has been taken by the mysterious "Helicopter Group" that trades with Janus, without sourcing the claim by an episode title or a Word of God.

What happened to Heath in-universe?

Answer 1

Possible spoilers for events of seasons to come (season 10+)

The only element tied to Heath's disappearance is the key-card labelled PPP that Tara found at the last place she was with Heath:

This card is

never discussed afterwards in the series, at least until the end Season 9.

Angela Kang discussed during an interview the fate of the character:

Showrunner Angela Kang has since confirmed the group who absconded with Anne (Pollyanna McIntosh) and a wounded Rick Grimes (Andrew Lincoln) aboard a helicopter are the same group responsible for Heath’s disappearance. “That was kind of the intention that we had in the back of our heads this whole time,” Kang revealed in November. “Even back in that season where you know we had to write the wonderful Corey Hawkins out because he had huge opportunities in the feature film world... those seeds were already set there.”

The PPP mystery will probably be answered later in the show:

It remains to be seen if Hawkins will reprise his role in the Rick Grimes trilogy of movies, the first of which will reveal answers behind the helicopter community and their mysterious ‘A’ and ‘B’ classification system as it follows Rick and Anne on a new adventure someplace far away from Virginia. (source: comicbook.com)