That's very interesting. I used Norbyte's ExportTool to extract DOSEE into a folder and looked into some of the files. There's a file found at \Public\Shared\Stats\Generated\Abilities.txt that lists all the abilities... save the very one you mention:
ability WarriorLore,0,0,0,0,0,0,0
ability RangerLore,0,0,0,0,0,0,0
ability SingleHanded,0,0,0,0,0,0,0
ability TwoHanded,0,0,0,0,0,0,0
ability Blackrock,0,0,0,0,0,0,0
ability Bow,0,0,0,0,0,0,0
ability Crossbow,0,0,0,0,0,0,0
ability Shield,0,0,0,0,0,0,0
ability Reflexes,0,0,0,0,0,0,0
ability ArmorMastery,0,0,0,0,0,0,0
ability Sourcery,0,0,0,0,0,0,0
ability Telekinesis,0,0,0,0,0,0,0
ability Willpower,0,0,0,0,0,0,0
ability FireSpecialist,0,0,0,0,0,0,0
ability WaterSpecialist,0,0,0,0,0,0,0
ability AirSpecialist,0,0,0,0,0,0,0
ability EarthSpecialist,0,0,0,0,0,0,0
ability Repair,0,0,0,0,0,0,0
ability Sneaking,0,0,0,0,0,0,0
ability Pickpocket,0,0,0,0,0,0,0
ability Lockpicking,0,0,0,0,0,0,0
ability Loremaster,0,0,0,0,0,0,0
ability Crafting,0,0,0,0,0,0,0
ability Barter,0,0,0,0,0,0,0
ability Charm,0,0,0,0,0,0,0
ability Intimidate,0,0,0,0,0,0,0
ability Reason,0,0,0,0,0,0,0
ability Charisma,0,0,0,0,0,0,0
ability Leadership,0,0,0,0,0,0,0
ability Luck,0,0,0,0,0,0,0
ability DualWielding,0,0,0,0,0,0,0
I find it very hard to believe that this missing entry disables RogueLore, but I suppose stranger things have happened. The modder in me says "add it and see what happens." I'd also scan all the other files to see if "RogueLore" or something similar is used anywhere else. Surely it is referenced somewhere in the code (and scripts) or I'd assume that none of the Rogue spells would function properly. I'll have to take a look myself as I'm currently planning another play-through. After all, I bought DOS2 many years ago because Larian offered a discount on it, but I've yet to touch it since I haven't finished DOSEE. :)