No idea, but it wouldn't be the first time Alex has said one thing, then done or said something to contradict it.
The claimant seemingly had to provide real identifying information to file this DMCA. This is something Alex would do and apparently has done in the past; I'm led to believe he got Rommel's YT terminated when he made The Rise And Fall of YandereDev which is why we now only have a Reupload. The way he writes also doesn't give me a sense of "is this actually him?" because he does write like that.
There's every possibility someone may have filed a DMCA under Alex's name because they have his personal details and copied his vernacular to throw him under the bus, but I feel that's less likely than simply just being Alex himself consciously taking it up to a platform's higher-ups to get it taken down. He wants censorship on his Twitter and has successfully censored his Instagram, so I wouldn't put it past him.