"Overall, we rate Truthout strongly Left Biased based on story selection and political positions that favor the left. We also rate them Mixed for factual reporting due to publishing a false story and promoting anti-GMO propaganda. (5/15/2016) Updated (D. Van Zandt 12/01/2022)"
That distinctly anti-science angle doesn't seem to apply here, so I'll allow it.
Blanket Anti-GMO hysteria is bad of course but there are arguments to be made against things like terminator seeds being used as monopoly tools and pesticide resistant GMOs enabling overuse of them.
Having skimmed through the article mediafactcheckbias linked, it's kinda weird. At first glance it seems like it's raising legitimate concern, but it never specifies what.
It sounds like it's making a case that modified Bt toxins could cause unexpected problems in the ecosystem or for other crops on the long run by targeting more insect species than what it's designed to, a seemingly valid concern, but never actually reaches any conclusion, instead it uses handwaves like "unexpected toxicological properties " and "protecting public health and the environment" which make it look like they want you to think GMO are poisonous to people without actually saying it.