They introduce the same method, but apply it to grammatical error correction, meaning the "draft" output is just the input itself. The Speculative Decoding paper tries to emphasize differences between this and their method, saying that theirs is more general, as they apply it to more domains, allowing the draft to come from a smaller model, and extend it to allow sampling.
All of that is great, and deserves another paper, but doesn't deserve the credit for inventing and rights to rename the method, especially when they were aware of Shallow Aggressive Decoding before uploading their first draft.