You couldn't up previous raid gear to the level cap it would render the new raid useless. Now you could raise the previous raid/raids to the lvl right below the current cap. For example you get Crotas end raid gear which gets you to 32. Thus you should bump the VOG raid gear to get you to 31 that way the gear is still relevant and the new raid is too. Do this every time a new raid comes out basically making a ladder. Until destiny 2 drops.