It has been said by both Kitase and Nomura that VIIR is not likely going to be a faithful retelling of the original, but will also add additional scenes to supporting characters and altered moments. So what do you expect to see changed?

Personally, I'm thinking this game will go the way of the Rebuild of Evangelion, starting off pretty faithful before going in a very different direction as early as the second Disc content before reaching a revamped final conclusion. With that said, I feel the safest assumption of something being changed is that Yuffie and Vincent are no longer optional, but will be integrated into the narrative better.

I feel one of the first changes we may see is that the Kalm flashback may actually play out in the first Episode in Midgard, and they may just completely skip over Kalm as a location. Similarly, I feel some sequences may be changed around, either playing earlier than the original or being altered and played later. I feel like Barret's whole backstory will likely all play out in his hometown instead of being spread out over the course of the Gold Saucer sequence. I imagine the whole Wutai events will be altered for the sake of condensing it down as a one way trip. I also imagine Fort Condor will be the first major change we'll see. It will likely be changed into a more story driven sequence and I wouldn't be surprised if they tie it into recruiting Yuffie since this region was the earliest you could recruit her.

Despite being episodic, I feel several sequences are going to get condensed down. Partly to scale back some of the fluff the original had, and partly to make room for new content. I also feel like the Compilation will get a few winks and nods, but will likely not show up in any significant way as some people fear. Of anything, I feel VIIR will more likely be incompatible with established VII canon as fans know it, and will be regarded as its own thing.

I keep thinking the Gold Saucer will also be completely revamped in some ways. Largely because it will be difficult to carry it's structure throughout all of the episodes. Of anything, since I really don't imagine there being a traditional world map. It's more likely to be open world like XV was with all the main continents probably segregated into their own episodes with no means of backtracking once the episode is complete. So anything that requires that kind of design will very likely be altered.

I don't think we'll see Bizarro or Safer Sephiroth, maybe something new, but something closer to Sephy's human form. I also imagine the final gimme battle against Sephiroth will be revamped into a full QTE style event designed to visually mirror Advent Children's main fight. I totally see the fight changing geographical locations throughout the battle as Cloud has flashbacks of his whole journey.

I expect the series to be seven episodes in total. Three episodes each to cover the first two discs of content and then the final episode for the last disc.