Is Matthew 27:52,53 describing a historical event? If so, why only Matthew recorded this? Who were those “holy people who had died were raised to life”? Does “raised to life” mean “resurrection” in such context?
Yes. Matthew’s account of holy people coming out of their tombs after the resurrection an historical event. Matthew mentioned it because he was writing to the Jews, whose ancestors were coming out of their tombs. I believe these people were the fulfillment of the wave offering that was presented before God at the feast of first fruits. They all went into heaven with Jesus when He ascended.