Actually I think he was referencing the latest comprehensive rules (9th of Feb).

513.2c Continuous modifiers from an effect attempting to modify qualities of objects don't affect objects that weren't affected when the continuous modifier was created.

Not clarifying from what he meant but just explaining it as I see it. His statement is a reflection of the rules in which WoS only affects army sentinel chars that are in-play at the time WoS resolves.

So if you played WoS, then recruits an army Sentinel character, the new army sentinel character would not get the continuous modifier from WoS.

Was referring to a different number (fingers liked 123 in succession apparently. ;)): 513.2c. And yes, WoS only applies to Army Sentinel cards in play at the time it resolves.