In some isolated places there have been periods of moderation. But always under subjection.
Problem comes when times are bad or bad rulers arrive, the seed of the genocide and massacres is cooked into their book.
There is no time when Christians are accepted as full equals.
Now, Egypt? Over time, huge spans of time they have seen a lot. They were a great civilization before Islam existed. Long Long before.
It may be as stated in the article that 10% of Egyptians are Christian. That is pretty high for a predominantly Muslim nation in the Middle East.
They have had leaders who tried to seek peace and understanding. Sadat certainly did, and the Muslim Brotherhood killed him.
Hate consumes. It destroys people and nations.