There are differences between Shia and Sunni as to incorporating holidays. For examples, The Day of Ashura. Interestingly, the two sects observe the day for completely different reasons. The Shias as commemorating the martyrdom of Husayn ibn Ali at the hands of Muwaiya's son Yazid. The Sunni's on the other hand observe it as the day the Israelites were freed. Additionally, Shia take this much more seriously. The Day of Ashura is followed by Arba'een, one of the largest re-occurring human gatherings on Earth in Karbala. Sunnis dont acknowledge this at all. If you look into why this is Shia specific, you'll see that it stems wholly from the history of Shi'ism. So by nature, this celebration is something that happened after the time of Muhammad ﷺ and the revelation- commemorating something that at its root isn't religious in nature, but rather political. Husayn, as far as Sunni are concerned, is no more venerable a figure just on the basis of his blood than anyone else.

But to better address your question, understand that Orthodox Sunni Islam is opposed to excessive celebration of anything at all that isnt religious. Birthdays, events, really any mundane earthly occasion. Many Sunni celebrate Muhammad's ﷺ Birthday, but even that is technically frowned down upon. The idea being that excessive celebration can lead to idolatry and misguided priorities. Along the same vein as with why Islam disapproves of nationalism. So the point being, incorporating pagan celebrations into the orthodoxy? Absolutely out of the question. I chuckle at the notion, haha.

That being said, while Muslims would not celebrate it, the Holidays of Christians and Jews were allowed and observed as far as the state was concerned. These two groups are deemed 'People of the Book', and there is actually specific instruction in the Quran to not impede in the faiths of these peoples, along with the Sabians. So while Islam would not incorporate things like the Sabbath, or Rosh Hashanah, they would still be observed by their respective observers.

I hope that sheds some light on your question.