ECW was so great it needed two promotions to fill the void it left. Ring of Honor is the successor to the technical wrestling and Combat Zone Wrestling is the successor to hardcore wrestling. Both promotions run most of their shows in ECW's home venues such as The Arena in Philadelphia and The Manhattan Center in New York. However, they didn't belong to the NWA and out of these two, only ROH has a television deal.
The UFC is considered by most to be the successor to Pro Wrestling in general, since it follows the same exact model, although lately they have been trying to move away from that structure.
Tongue in cheek all women's promotion GLOW spawned a number of spiritual successors, such as POWW, the LPWA, CRUSH, Women Of Wrestling and Wrestlicious. Despite their names and premises, SHIMMER and SHINE are not examples, instead being recurring showcases of the best and the future of the business. The names are slightly coincidental but GLOW is an acronym, the latter two's are SWA and SW. Since SHINE partnered with Big Vito's school and SHIMMER has the ROH Academy, they could conceivably become spiritual successors to GLOW but they have a tendency to send their rookies out to the wider industry, GLOW was rather isolationist.
SHIMMER is more so the spiritual successor to IWA Mid-South's Volcano Girls, another project in Ian Rotten's quest to show his promotion was not just for garbage wrestlers and an early step in Dave Prazak's to cater to wrestling fans who wanted to see more from the women involved in the sport. It also featured several wrestlers who would later be in SHIMMER, co founder Allison Danger not the least of them.
A humorous case happened in the 2000s to early 2010s when the NWA launched a revival of Championship Wrestling from Florida and The WWE launched a revival of Florida Championship Wrestling. For those who don't get it, they both ran revivals of the same company at once. CWF had been erroneously called FCW for years and was forced to temporarily change its name to FCW for a time in the nineties.
After joining the NWA in 2013, All Action Wrestling declared they would be to Australian wrestling what NWA World Championship Wrestling used to be in the 60s-70s.