So let me get this straight...

ZOINKS! We’re adding a new mystery champ item to the store for RP or IP in a future patch that’ll help offset the RNG of finding champ shards and permanents in chests

http://na.leagueoflegends.com/en/news/game-updates/patch/patch-610-notes

I imagine this will either come out in an update later this cycle, or in the next patch. It doesn't seem like something they would delay on, seeing as they had this plan since they announced the system to unlock the next tiers

Not exactly. For instance, you can't randomly get to Mastery Level 6 or 7 if you never get an S- or Above with the Champion.

That would have to be the case for it to truly be Random.

While obtaining the tokens isn't random, the second part of it, looking for the material to fuse the mastery tokens is.

Hey, you can always disenchant those champions you don't want into the blue essence for fusing mastery 6 and 7.