  With all the connotations in the story about weaving, patterns, age lace, individual threads(lives) and ta'veren being able to make the choices that change the pattern, I dont see how it would be that difficult for a ter'angreal to predict a possible future based on present events, and how they would come to pass if things were not changed. It isn't really a question of what is possible, it is a question of where the information is most easily accessed. Everything required for pre-ToM operation can be found in "Old Blood." Nothing required for post-ToM "operation" can be found in "Old Blood."  