I suppose they only did it now due to some license agreement expiring?
Yep, if I understand it right, Denuvo charges an annual fee to be used. That's why you always see it getting removed after the game loses relevance, when sales aren't enough to justify paying for Denuvo anymore.
Kind of weird how, because Bethesda (and other publishers) are Denuvo's consumer, this particular anti-consumer license agreement is actually benefiting the players, haha.