In short: There may be at least one more Chrome OS device with LTE connectivity in the works and similar in build some prior CTL-branded devices, based on a couple of recently spotted additions to the Chromium Repository. The code commits in question reference a Chrome OS device bearing the codename "BlacktipLTE," based on the "Blacktip" model, and built on the "coral" reference board. The code in question also designates the new build as a "white label" device, which would seem to indicate that it is intended to be used as a base design from a single OEM to be rebranded by others prior to sale. Meanwhile, a secondary white label tag within the same code could point to CTL as at least one of the brands associated with BlacktipLTE or possible the manufacturer set to build it. Looking past the naming conventions, another commit suggests that it will require changes to the Chrome OS firmware used for coral, in order to support the same modem configuration as an LTE-enabled device codenamed "astronaut." Both of those clues strongly implicate a Chromebook with an LTE-capable modem for connectivity via a mobile data network.
Background: There aren't too many other details that can be ascertained from the commits for the time being. However, astronaut is the codename that has been associated with Acer's Chromebook C732, designed primarily as a Chromebook for use by students or others on the education side of the market. Acer's device specs center around a quad-core Intel Celeron N3450 processor to the table with a base clock of 1.1GHz backed by 4GB of LPDDR4 RAM. It also ships with LTE-compatibility. There's no guarantee that the new devices will feature the same hardware but the implication is that the same modem configuration will be used.
Now, Chromebooks with options for connecting to the internet other than Wi-Fi are nothing new. Not only has Samsung recently announced an LTE-enabled variant of its Chromebook Plus V2. Google's original Chromebook Pixel and HP's Chromebook 14 (2013), in addition to a few other models, have offered the capability prior to that. However, LTE certainly hasn't been a part of the mainstream in terms of connectivity features for Chrome OS devices.
Impact: Bearing that in mind, with the introduction of Samsung's Chromebook Plus V2 (LTE) and the current expectation that Qualcomm's Snapdragon processors will soon join the Chrome OS mix, this could just be the beginning of a new trend. Chrome OS is heavily reliant on a stable internet connection for a huge number of its features, including many of the Android applications that can be found on modern devices. So mobile connectivity becoming mainstream would be a serious bolster to the ecosystem itself, as well as a high-value selling point for those manufacturers who implement and popularize it first.