Not retroactive, they are adding the weapon materials to the new DD zones not yet released.
They should have done it for the first batch of higher skill 119 weapons, when they went from skill+224 > skill+242. +269 REMAs should be further above that. Armor stat vomit made similar increases at the same time, but armor doesn't have a simple marker to look for like skill+#, which can be confusing at times. And you are right to doubt ilvl being raised at this point, given that the devs seem to be openly adamant about being against doing so.