According to Marcus Sellars, an industry insider who also works for various Nintendo sites, Treyarch is hard at work on Call of Duty: Black Ops 4, which will likely arrive later this year, in the same timely fashion as other entries in the ongoing first-person shooting series. Treyarch's Black Ops 3 was released in 2015, Infinite Warfare from Infinity Ward was released in 2016 and previous year we went boots on the ground with Sledgehammer Games Call of Duty: WWII.
Interestingly, it looks like Black Ops 4 will also be taking a similar approach to Call of Duty: WW2 with its "boots on the ground" but this time in a modern setting - which is definitely music to my ears. With that said, take the following information with a grain of salt.
Much of Sellars' report was based around the Nintendo Switch version of the game.
There is no question Black Ops 4 is just as good as good as Call of Duty: WWII. For that matter, Call of Duty: Black Ops 4 could serve as the ideal game to get people on board for Nintendo Online when it arrives.
If you don't know, Marcus Sellars is the one who predicted the January Nintendo Direct date a month before it launched, and he's also the one who happened to be right about Nintendo's Labo announcement. "The Switch version is being ported by a company already familiar with the Call of Duty titles and will be fully featured, including support for HD Rumble, DLC and motion controls". The new title is said to offer a "boots on the ground" experience, meaning that forward-thinking equipment like jetpacks seen in titles like Advanced Warfare may not be present.
With Treyarch in charge of the next Call of Duty it comes as no surprise that the next entry into the series will be Black Ops 4.