According to Vince Zampella, the founding CEO of Respawn Entertainment… so this is not a rumor but official information!
Steve Fukuda was the director of the two Titanfalls, and it’s safe to say that he did a good job, especially on the second installment. True, Electronic Arts sandwiched the release between their own game, Battlefield 1 by DICE, and Infinity Ward’s Call of Duty: Infinite Warfare. Unfortunately, the mech action sank despite the excellent reception. (Perhaps that’s why the battle royale spin-off Apex Legends was created, and unfortunately, the single-player Titanfall Legends project was canceled…)
In an interview with Axios, Zampella was asked about Battlefield, Star Wars Jedi: Survivor, and Titanfall. Respawn Entertainment is currently working on two Star Wars projects. One will be a first-person shooter inspired by the Jedi Knight games. While there would be a demand for the studio to work on Titanfall 3 (Zampella himself would like to), that is out of the question because it needs to be timed appropriately.
Consequently, they have learned from the Titanfall 2 story (where the fault lies more with the publisher, Electronic Arts because EA is partly to blame for the failure) and do not want to release when the possibility of success is simply overwhelmed by the crowd. Of course, it also requires that Electronic Arts, who own the studio, not only see the Ultimate Team constant cash cow but also give way to single-player, offline (beyond DRM…) titles.
Fukuda is currently leading a small team at Respawn with a mission to embed something new in the future, so the studio is letting him create something new. They should because the studio will surely get bored of the constant Star Wars and Apex Legends development after a while. However, let’s not hope Fukuda’s plans will come to us anytime soon. It’ll take 3-4 years, so maybe it’ll be the next console generation before we see what they’ve come up with.