I think it’s fair to write a post criticising systemic, terrible things like racism, abuse, toxic work culture.
But this just reads like a shit deal in a tech company. To his point, others could have different experiences.
So why write it at all?
Submit the glassdoor review and move on.
OP I know you’ll probably read this - so don’t be too hard on yourself in regards to my reply. You’re starting a new adventure and I’m excited for you.