Hi, yhcho15
Dear developer, welcome to the Microsoft support community. It's good a demonstration of professionalism that you consider the copyright regarding to the work of Microsoft.
However, You problem is about the usage of the open source fluent emoji which is under fluent Ui developed by Microsoft, right? If that is the case I am afraid this is out of the scope of this forum; this is supposed to be a forum to ask technical problem about the product of Microsoft like windows system and office for example. While your issue is essentially an license issue about a project developed by Microsoft, in this case you should referring to the license itself(MIT, if I have it correctly).
Regarding to your usage the situation might be very different. Form my briefly search I found some information just as a rough reference:
There are generally two type of license: permissive license, copyleft license.
- permissive licenses, like the MIT license, provide users with greater flexibility in using and modifying the software,
- copyleft licenses like GPL require your project to release under the same license.
This is just for a simple insight which I cannot grantee the reliability of this, and sorry that I do have the right to direct you to some third party site; feel free to go to some site like Github to learn further, specially check the source repository of fluent emoji and you might found the license and legal regulation it declares( which I found a lot of information that might clear your issue).
Moreover, I suggest you search the key word commercial, open source in your desired search engine to learn the detail. It’s always a good idea to ask the search engine about some thing beyond your specialty.
I hope you can solve your confusion soon, have a good day. If I have some mistake in this post feel free to reply and let me know, that way we can grow together.
Benjamin- MSFT | Microsoft Community Support Specialist