You could get blocked from using it.
Face higher sanctions, since most of GQL doesn’t work with a normal oAuth token.
Risk of functionality as undocumented endpoints can and will change at any point.
Also additionally to figure out how GQL operates you technically broke the developer TOS by reverse engineering the Twitch Website to determine how the calls work and are made.
Main TOS: Section 9 vii
vii. reverse engineer, decompile, disassemble or otherwise attempt to discover the source code of the Twitch Services or any part thereof, except and only to the extent that this activity is expressly permitted by the law of your jurisdiction of residence;
Developer TOS: Section 3
3. Limitations. You must comply with all instructions and requirements in any integration documents, guidelines, policies, or other documentation that we provide or make available to you. You will not reverse engineer, disassemble or decompile the Program Materials or otherwise compromises Twitch’s rights in the Program Materials ~snip~