Kirk: huh? not a damn thing for season 5 gets spoiled in 'Deconstruction'. what are you talking about? The Garibaldi scene? If so, that spoils nothing at all.
To kirk, anything
revealed beyond the "present" is a spoiler, hence his reaction to Londo's fate, hence his reaction to being told vaguely when B5 is destroyed. This... isn't a view most take, I don't think.