You can find my theory on the matter here:
http://forums.spiralknights.com/en/node/92203#comment-820098

I've posted it hundreds times. Other people have posted it as well. Yet there are people who can't read so let me repeat myself:

According to Nick announcement that new boss will be T3 boss - that means it's THE SAME DEPTH as Fire Storm Citadel and that means the Fire Crystals drop rate will be exactly the same.

The bunch of new missions between FSC and new boss means nothing - there are many rank missions between RJP (rank:Knight) and IMF (rank: Elite Knight), yet both those bosses are exactly at the same depth and have exactly the same crystals drop rate.

So, unless devs will change theirs minds and make it out of the sudden a T4 boss OR unless they decide to screw consistency and make an unique level with different drop rules then other levels at the same depth have, NO there will not be more Radiant Crystals in that new boss hideout.

Exactly what I've been saying:
"t2 had jelly king as well as roary bros" - note that they are both at the same depth and with the same crystal drops.

New boss will be at the same depth as FSC. And will have the same crystal drops.

I suspect the developers have a sort of indirect means of adjusting crystal drops. They don't, like, pick a depth and then pick a droprate for crystals on that specific depth. Instead there is most likely a config file. The file may have looked something like this at some point:

crackedCrystalRate = 0
dimCrystalRate = 0.25
warmCrystalRate = 0.2
glowingCrystalRate = 0.15
shiningCrystalRate = 0.1

With radiant drops not being defined 'cause they'll just be the rest. (0.3? If the numbers follow a form as this, they might be supposed to add up to 1.) There's some kind of obscure formula in the server-code turning these numbers into actual droprates. Maybe some hidden number goes up by each depth and when the droprate for a given crystal gets insufficient, you'll stop finding them at certain depths.

The employee at OOO adjusting these config files are probably not intimately familiar with how it works under the hood.

So they listen to feedback, right? We're kind of peeved beause shining crystals are really rare and can only be found at, like, two depths. Eventually, the employee goes ahead and adjusts the rates again, to try fixing the shining fire crystal rate, increasing the rates of all the lower crystals while he's at it:

crackedCrystalRate = 0
dimCrystalRate = 0.3
warmCrystalRate = 0.25
glowingCrystalRate = 0.20
shiningCrystalRate = 0.15

Where there used to be 0.3 left for radiants, there's now only 0.1. Well-intentioned, but they had no idea what they were doing.

You see examples of messing around with numbers that aren't understood all the time. See Brandishes vs Levi, Dazzling Light Ray vs Disintegration Ray, and basically the entire mess we sometimes refer to as a 'balance' for the lack of a better term.

@Spectre-Nova
No. When you've stacked code upon code upon code for so many years, you begin to forget how things work. Even re-reading documentation that you yourself has written becomes painful, and sometimes misleading.
Fixing internal mechanics is a pretty horrible task, I can understand why Three Rings is excited to make new content rather than slog it out trying to find the needle in the haystack of where the bug is.