Sequels don't have to happen directly after the originals to be 'true', not sure where you got that from, tbh. With that in mind, these could possibly be the first 'direct' sequels, although at this moment we don't know what the heck will go on.
You're acting as if these will be the first sequels, period. They are not, though. Them being in the same gen doesn't mean they are any more 'real' sequels than GSC. That's what I'm trying to say.
No what I'm saying is it seems its the first time they wanted to make an obvious sequal. Like I'm not sure if it will keep Touya or Touko's story going or if its based on a new hero. Thats what I mean by it being a first. It would be the first time you play as an old hero perhaps.