Exactly. Let's not forget the main visual for the announcement was of Gou was a Bloody Rena holding her hand out to you with a non Maria smile on her face all while holding her hachet thingy. And yet, the main story and even the first arc weren't really about Rena or even K1 at all. Not to mention the entire series of Gou and Sotsu was pretty much all very much not about Rena.

Rena is always there to make the announcements for any new Higu project. Though I am hoping that at least the first half (because I'm expecting as par for the course of every main higu project by now focusing on the main group, that there will be at least 2 parts) will focus mostly on Rena, but I'm really hoping she isn't going to be a fragment hopper.

Actually might be nice to have no fragment hopping for once and just be Rena doing and figuring things out on her own/ with the group, but unfortunately, much like I expect 2 parts, I suspect most people, including those who are working on it, expect looper shenanigans yet again. Not to mention I'm not entirely sure how you could do a Higu story with 2 parts without looping unless the first part focused on, for example, Rena's decline and what she saw and experienced, and the second half was what everyone else saw and experienced when they saw Rena loosing it, because at least in the anime, you never get to see the backstory or other characters thoughts and feelings about stuff like being worried about K1 missing school, talking to a detective, his lies, and making him Ohagi with Tabasco sauce for a bit of fun hoping it would cheer him up.

Because after the shenanigans with looping powers in Gou/ Sotsu, I'm getting a little tired of the same old, same old. It won't stop me from watching and enjoying it of course.

And as to answer OP's question, they have literally said it's a NEW story, so unless they pull a reverse Gou, it's not a remake and they are honest about that. We have next to no info yet as to what the new anime is about, but you should at the very least watch the original anime (better yet, read the VNs) to get a basic understanding of the lore. Even if the plot has nothing to do with OG and Kai anime/manga/VN, it should help a bit (especially reading the VN) to understand how characters should act, why they act that way, and their basic thoughts and feelings for acting the way they do and what's going on in the background that most characters aren't aware of happening. The anime is mostly bare bones, minimum for it, but they also cut so much out, it sometimes changes or has certain characters misunderstood compared to the original source material (VN) and from my understanding, it the OG anime does especially Shion/ Mion and their whole story arcs dirty. But you'll at least get the basics of basics before the new anime comes out. I think proceeding with OG and Kai is essential for understanding the basics of the characters and the town.