This was all by design.
The article is funny because it highlights the pisstaking, but really they’re playing babyface and heel at the same time and relishing every type of reaction, because it’s all eyes on them at the end of the day. Every time someone shares an article/tweet/video with their ridiculous/progressive (you choose) statements about inclusivity and social issues, it encourages someone to share the article with another group of people.
What is marketing? People knowing your product exists. You want them to remember. It’s not ever going to be about social issues, that’s the bait that makes you tell your friends. The next time you’re in a shop, people will notice the M&Ms and that’s already a victory. They manipulated you into marketing for them for free.
How many boycotts do you think this will get them? Will they last? Compare that with how many people that will think “I love peanut M&Ms, but it’s been ages since I had some” and will now buy a bag.
Mars has good marketing people.