I personally have a habit of seeing each title as a pocket universe. It's hard for me to believe that old games, retellings and reimaginings can be part of the same continuity because of how they differ in tone, approach to different aspects and vision in general. And the same goes for other games as well. If we take titles like Resident Evil (2002), Resident Evil 6, and Resident Evil 7, for example, then it's also hard for me to believe that they represent one universe. Each game tells and shows a story and setting that feels natural in itself, but when you try to compare these aspects between titles and see three different Redfields, it's kind of a suspension of disbelief for me.
Do I want to say that the mythology of the Resident Evil universe is a mess? No. On the contrary, I strongly believe that the lore of this universe is incredibly consistent, which is an anomaly for such a large franchise that so many authors have worked on. If we take Metal Gear, which had Hideo Kojima almost all the time, even this series is less consistent in what it did.
But I feel that every story that this or that game tells us is somewhat unreliable, so we
always have a chance to see a retelling of it in a different shape and form. And for this very reason, it's not a big deal to me that Chris changes his face and voice almost every appearance.
I am betting this will feel disconnected from Darkside Chronicles with Krauser being reimagined.
It's very possible for sure.
This is a well-known fact, but I think it is sometimes useful to look at some stories without taking into account extensions that were written retroactively, because the authors who wrote them back then could not expect you to know those things that will be established in the future.
Does this mean that some untold story between Leon and Jack could be important for the narrative of Resident Evil 4? I think not, because there is no point in relying on non-existent things. Such a story is something that could give more substance, yes, but it is quite clearly not necessary for the story that Mikami-san told.
Shinji Mikami told the story of how Jack Krauser kidnapped Ashley to earn Saddler's trust, since he was a double agent and Wesker's lackey. The very idea that Leon and Jack worked together before the events of this story could have been written as a way to tell the players Wesker's plan to resurrect Umbrella, because Jack would not say such things to someone with whom he does not have a proper relationship.
In other words, if Mikami-san had found another way to give such information, I believe Kennedy and Krauser could have met for the first time at all, and the narrative would hardly have lost something important. Maybe it will even improve the storytelling, because meeting Krauser in this game is like if we met Wesker in CODE: Veronica without the first game.
And I think I've described a perspective that developers can easily choose because they're remaking specific narratives.
In fact, this perspective is also the reason why, for example, Ada Wong pretended to be an FBI agent in a new interpretation. This is an idea that, in my opinion and the opinion of the developers, works better for the Resident Evil 2 story, but in return you sacrifice a callback to another title.