Flashpoint has become one of DC's most iconic storylines/events, with its alternate universe inspiring various adaptations outside the comics. The story of said world also continued in Flashpoint Beyond. It's not the only iconic event DC followed up with a sequel, with Dark Crisis doing the same for Crisis on Infinite Earths.
Source:https://www.cbr.com/flashpoint-beyond-more-dc-comic-events-deserve-comebacks/