ThePrimeagen asked to do a react to one of my videos, this goes out not just to him but everyone else, as long as you're not uploading the video 1:1 it's free real estate, do a react, meme edits or whatever else you want, all of it is fine with me.
@BrodieOnLinux Still nice of him to ask. I saw a lawyer YouTuber explaining that react videos are a very gray legal area of copyright and fair use is basically case by case. Technically you are entitled to ask payment from a react video, if you so wished. Some people out there do upload videos in full and monetize them against the creator's will. Making sure everyone involved agrees on the terms seems like good practice.
@stringz I get that, I just don't care for my content