There has been a long process of catching up the console version to the PC/Mobile version. I keep track of the weekly developments over here:
We’re actually closer to catching up than we’ve ever been before and over the next few weeks, will continue to close the gap. We’re scheduled to get Silverglade on Friday and at that point, we’ll be ahead of PC/Mobile on features, even on Kingdoms and just behind on about 20 troops. When I joined the game, we were about 6-7 months behind PC/Mobile, now, we’re about 12 weeks behind on troops (and they are only adding one troop per week now) and caught up in every other way.
Adding new troops to console requires a client update. This means that any troops developed after the last update we downloaded cannot be added.
If they added all the troops each update to chests immediately, it would give the players the impression that there is no new content being added to the game for long periods of time. PC/Mobile doesn’t have to deal with this because they can add new troops without a client update.
Personally I’d be okay with them just adding everything to chests immediately and have all glory troops released be things that have already been put out in chests, but I guess the devs determined that wasn’t an ideal solution.