I wondered why Fawkes didn’t come and revive Snape but he led such a sad life with his unrequited love that he wouldn’t have been happy. I wonder if he’s in a portrait in the headmasters office?
It didn't mention his portrait at the end of the book, and I wondered if that were because he was imposed on the school by the Ministry of Magic, and it was the school's way of not recognizing him as such. But Harry did remind his son, before he went off to Hogwarts, that he was named after two of the school's Headmasters.