Meghan Markle’s return to the UK is “not ruled out” as the Duchess of Sussex is set for a major appearance. Prince Harry is set to speak at the Invictus Games 10th Anniversary Service, which will be held at St Paul’s Cathedral on May 8. According to a copy of the official St Paul’s Cathedral schedule, the Invictus Games event is listed for Wednesday, May 8 at 5pm. Prince Harry and Meghan Markle are listed as guests on the official running order. However, the Duchess of Sussex is listed as a TBC (to be confirmed) guest. The Duke of Sussex, who founded the Invictus Games in 2014, is set to speak…