No it's not a remake.
It's just a PS4 port of a PC port of a PS1 game. Producer Shinji Hashimoto has promised us that this PC port will be "exclusive" to PS4, for all the logical sense that makes.
Yes, they shoved this guy onto a 13 hour flight to Las Vegas just for him to announce this.
Don't worry, I'll follow up with any important updates later on. If Hashimoto is forced to escape lynch mobs by running across the Mojave Desert, I will let you guys know.
Now if you excuse me for a moment.

Why remake when you can get people to just rebuy without any major updates to it? 

Like, you're right that even if it sucked we could still go back to the original. But there is a chance of canon being fucked with and that is worrying. It's like how people argue over the star wars trilogy. You've got old fans (original trilogy) battling the latest movies with what's canon and it's fucking infuriating to have to say 'well, that's a retcon.... no, that was changed' to newcomers. 