It is not at all new that a company like UMG has used the DMCA to censor or remove content they do not own the rights to.
What is new is that someone is actually attempting to punish them for it.
They've been doing this exact same thing as a matter of course every day for a decade, and this is sincerely the first time I have ever seen anyone attempt to enforce the clause that is supposed to punish them for it.
Companies like UMG wholeheartedly believe that the DMCA is carte blanche to remove anything they want from the internet without consequence. Until now, they've been allowed to act upon that belief freely, and the worst outcome for them has been that a counter-notice would restore the content a couple weeks later.
Hopefully everyone remembers when Viacom sent out a mass of DMCA notifications and removed tens or hundreds of thousands of videos from youtube? Hopefully they remember that the vast majority of them contained no material copyrighted by Viacom, and some didn't contain anything that was even capable of being copyrighted by anyone? Remember the $0.00 in damages Viacom had to pay for history's most egregious violation of the part of the DMCA meant to punish notifications given in bad faith?