They shouldn't have used the Sonic R "R" at all. Riders didn't need to do that (and it was called "Sonic R Extreme" at one point), nor did Sonic Rivals (which is more in the vien of Sonic R). It just feels like Sega went "Hey Sonic Generations, Sonic Mania, nostalgia sells!" Nostalgia is a great thing if done right, but if they just lazily dump it onto everything new, then it's going to be drained of all it's power. It's like Green Hill Zone – it's been lazily used so many times, that's it's gone from being an emotional part of the franchise to an annoyance.