increased duration most likely breaks the way these items are coded or heavily nerfs them so its probably intended. both healing rite and rescue beam are set healing values given over a span of x time. rescue beam for example heals 20% of maxhp over 2.5s, if superior duration extended this, should the item heal 20% over 3s (a nerf), or should the item heal more than 20% maxhp because the duration is higher?
If the 2nd, healing booster + superior duration could be incredibly strong on these items that are already very good support tools, if the 1st then it makes it a big nerf for support heroes who want to invest in other abilities/items durations without ruining their heal. probably better left as it is
