Deus Ex: Mankind Divided was good, but for a variety of reasons it wasn't exactly a big hit. That led to rumors in early 2017 that Eidos Montreal, which had previously positioned the Deus Ex series as its flagship, had basically shelved it in favor of other things. There hasn't been much said about it since, but studio head David Anfossi recently told PCGamesN that while Shadow of the Tomb Raider is currently the big thing on the Eidos plate, "Deus Ex is not dead."
"Deus Ex, of course, it's the brand of the studio. We are all attached to this franchise, but we cannot do everything, you know?" he said. "So we have Shadow of the Tomb Raider, we have this co-development with Crystal [Dynamics] on The Avengers, and we have a third game in development, so it's enough at the moment for us."
That third game is rumored to be based on Guardians of the Galaxy, although it remains unannounced despite the initial report of the project being well over a year old now.
The news is somewhat less happy for fans of Thief, which didn't get the same "not dead" seal of approval that Anfossi offered Deus Ex. He repeated the point that Eidos Montreal is already focused on three other projects, but concluded, "For Thief, there is no plan." Although given how the last game worked out (it's a reboot that eschews the original trilogy in all but name), Thief fans may not think that's such bad news at all.