JClosed: Well - I have to be honest here. I am a guy that always buy the games I like. I payed for Ys X and are happy with it.
However - If they do not offer this upgrade for a reasonable price (say €10 to €15 max), then I won't buy the game. And it will make me so pissed-off that I will obtain the game "by other means". I never ever do that with publishers I like (Falcom in this case), but if they going to act like jerks, then I going to act like a jerk too. It's sad, because Falcom is one of my favorite game developers. But if they want to take a arm and a leg from people that always supported them by buying their games, then they have lost their credibility in my eyes.
Hell - Even Gust with their Atelier series gave the DX update for their older games for free (I would love to see the Atelier series here on GOG by the way). So if GUST and their parent Koei tecmo is able to treat their customers right, then sure Falcom/Nisa could do the same?
For now I wait until we get some more news about this case. I hope they do the right thing, otherwise I would be really highly disappointed. Let's hope for the best...
ATLUS did it first with the Persona games so probably it seems Falcom got jealous. Anyway I would also love for KOEI Tecmo games to come here. They don't have any big DRM like denuvo so it could be possible if GOG wanted to strike a deal with them. But looking at the GOG dreamlist it seems there is not much interested for KOEI Tecmo games (I am very interested in the Toukiden games)