And to address several topics at once I've seen in the thread here, USF and IoA was not designed as an alternative to the "family" rides of WDW, they were designed to one up Disney in all departments (famously they wanted their hot dogs larger, their restrooms with more stalls, and the paths bigger) with the Jay-bang flair. IoA was a direct response to complaints and issues with USF; people wanted outdoor attractions, coasters, flat rides, and water rides. IoA was in a spot where all but TWO attractions would close in the rain, now that count is up to four.
Dueling Dragons is an ok B&M inverted coaster, it's not the best nor the worst. Dueling shouldn't have been removed as that added a lot of the thrills. Universal neutered the coaster and B&M was not happy about that and rumored to look into legal action. B&Ms rumored threats, maintenance issues (UOR's fault for sure), low guest counts (UOR's fault for a poor new entrance), WB's disappoint in using metal detectors, and the desire to round out the park with an indoor attraction puts DD on the chopping block.
Universal picked its language very carefully for their blog post, it made sure to highlight that this will be a coaster, that this will be heavily themed, and that it will be family friendly. Universal's definition of family is very different than Disney's and I don't think we're going to be working with a Gringotts or SDMT style coaster here. Each of the points Universal highlights also covers the issues with a DD replacement: this will be a coaster, it will not be over retention ponds and grass, and it won't scare the pants off of Michael Gambon.
Last point with UOR is there are consistent and predictable arguments against their attractions whether they are deserved or not. In the early 1990s the attractions didn't work as reliably as Disney's, in the late 1990s and early 2000s it was Universal "just built unthemed steel coasters" (remember THOSE complaints?), Universal didn't built new attractions and just did overlays, and now Universal just does screens. I get those who will miss DD and want a more intense experience, but please remember there are many who view this attraction as a DETRACTION to the park.
You are taking one data point and extrapolating a trend for both UOR and SeaWorld. I get you are disappointed about this change but nothing about the UOR or SeaWorld parks is fundamentally changing. SeaWorld opened Antartica and is still going to add Sesame Street and a river raft ride. Universal rebuilt the Hulk and is still going to be adding new coasters (two of their next four park projects are coasters). The new attraction will not be a B&M Invert but it doesn't automatically mean it won't be a physically intense coaster. I have seen many posters already jump to major conclusions on this attraction and UOR's plans; just chill out. I get that we don't have all the answers or information right now but we should not spiral into doom and gloom or uncheck euphoria.