That's what was thought, but maybe not -- only one of the three so far looks Epicurean, which is not what was expected. Maybe it's a fluke, but historians are buzzing a bit about whether it might be broader than expected.
The Epicureans were particularly hostile to the Jews and Christians, because Epicureans deny Providence or the active intervention of the divine in human affairs. See Horace Sermones 1.5.
It's more like the Christians and the Jews were particularly hostile to Epicureans and Stoics, because those mocked the claims about the existence of an all-powerful God that requires prayers.
The Epicureans and Stoics did not care much about Christians and Jews, but after the Christians obtained the power in the Roman Empire they made great efforts to persecute and discredit the Epicureans and the Stoics, as the most dangerous kinds of non-believers. (Unlike the rational Epicureans and Stoics, the traditional polytheists could be much easier converted to Christianity, by inventing a set of Christian saints to which the former polytheists could redirect the prayers and the holidays to which they were habituated.)
The Christian propaganda has created a false image of the Epicureans, which has persisted until today.
The Epicureans were not atheists, but they had a very different conception about what Gods are. They thought that in nature there are a lot of entities that have a god-like power, i.e. humans are too small and weak to influence them in any way, but the life of the humans is strongly dependent on the actions of those entities, so they can rightly be considered as gods. Examples of such entities are the Sun, the Moon, storms, volcanos etc.
Unlike in the traditional Greek and Roman religions, where it was believed that for each such natural phenomenon there exists some sentient god, who can be convinced to change the events to a more favorable outcome by prayers and sacrifices, the Epicureans believed that the gods, even supposing that they were sentient, in any case they do not care about humans more than humans care about ants, so there is absolutely no point in praying to them or bringing sacrifices to them.
Therefore humans should conduct their life according to ethic principles, but without worrying about what gods may think about their actions.
Many modern humans would probably agree with the Epicurean philosophy, which was completely different from what the Christian propaganda claimed, e.g. that Epicureans were some kind of sinners addicted to pleasures.
in the paper it says "The recovered text is a philosophical treatise on ethics, and the evidence points to a Stoic work: it turns on human nature, impulse, and the moral progress of human beings, and its final preserved column names Aristocreon — nephew and disciple of the great Stoic Chrysippus — which, together with the language and themes of the text, places it in a Stoic context and dates it to the 2nd century BC."