While I do like Tracey and would love to see him return, I'm not really sure if it's going to happen (at least not in a major way).
Tracey hasn't had a speaking role since AG192 "End of a Journey, and Then the Start of a Journey!" (which first aired September 14, 2006). He hasn't even made a cameo in the main series since BW142 "My Dream, Pokémon Master!!" (which aired September 26, 2013) and even then it was only in a fantasy. He hasn't appeared physically since BW116 "Burn, Charizard! VS Dragonite!" (aired March 7, 2013). However, he did appear in the credits of the "I Choose You!" movie, but all the travelling companions appeared in "I Choose You!" so it isn't very special.
When it was first announced that Misty and Brock were returning and we were getting 2 episodes in Kanto in Sun and Moon, I was pretty excited and had quite high expectations. For one, I expected all of Ash's Pokemon to make a cameo appearance (even if it was just a photo like at the end of BW) and I also expected Tracey to appear (he works and lives with Professor Oak, so there is literally no reason not to!). So when I watched the episodes and my boy Tracey was nowhere to be seen, I was very disappointed.
If the anime staff didn't bring back Tracey when they had THE PERFECT OPPORTUNITY TO, then I have little faith that Tracey will appear in the future. I don't even think the new anime with the "all regions" thing will bring him back, since he was literally just a replacement for Brock (by far the most popular male companion) in an anime-only region, so I don't think he'll be brought back in any major way.