Since StackOverflow won't let me Comment, https://github.com/Microsoft/vscode/blob/master/LICENSE.txt is the link to their License.
Which states:
MIT License
Copyright (c) 2015 - present Microsoft Corporation
All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
So, I think they might be in violation, as their software doesn't seem to be opensource? I'm not a lawyer though. They also have a Github, https://github.com/egret-labs but it does not have this product on it, meaning you would have to install the product in order to figure out if it has this license information included with the install or not.
This company just seems really shady though, due to them advertising VSCode features as if they are specific to that editor. It looks like the have added some minor features, specific to their project, that allows the user to create projects, for their special project format... but the way their white paper describes it, makes it sound like they wrote it by hand, which i'm sure they didn't, as it's an exact clone of VSCode. http://edn.egret.com/cn/docs/page/936