There actually was a conscious effort by plenty of online personalities to hold off on the whole "Aerith" thing when the remake came out. Sure if you dont wanna be spoiled by something dont go online until you finish what you dont want spoiled but also dont be a dick and go "lol wit this game is 34 years old how could you not already know." To someone that very simply might not have been exposed to the game or the franchise before.

If you go to the XC2 image gallery, you'll see tons of Pneuma and Blade Nia images that aren't spoiler tagged, even when they were all still in just 1 image gallery. And that game is less than 3 years old compared to XC1's 10. So there's no point in spoiler tagging Fiora pics.