My AP champion pool I used Magus with any regularity 
My new AP champion pool with Runeglaive
Everyone else I'll just use Cinderhulk or not build a full jungle item because there are better options.
PS> WTH with items not being grayed out while on cool down? Why change it? It wasn't broken.
All of those guys are better with Cinderhulk.
not sure what riot was getting at with runeglaive. they say its for junglers with poor clearing but after the first few clears, any champ can jungle really making runeglaive kind of pointless. It just cut down on jungle diversity if anything
Amumu, Cho, and Sej all use autoattacks in their rotations NORMALLY (Amumu passive, Cho E, Sej W); Elise normally throws in a few autoattacks, and Fiddles can throw in an auto before Drain is even off cooldown up until max rank ~20% cdr.
Honestly, i wouldnt build it on any champion because it takes the spellblade slot which can be filled with much better spellblade items, namely lichbane.
Sej, Cho, and Mu scale better with Cinderhulk than they ever did with Magus, so there's those...
Elise scales incredibly well with the new item since it adds to her burst and her kit is almost pure burst with a little bit of sustained damage with the AA's and spiderlings, but this really brings out her bursty side early on.
That leaves Fiddle. Fiddle is the only one who got the shaft with this, but at the same time, most Fiddle's don't get their jungle item to begin with. They get the upgraded smite, then rush a Zhonya's since Zhonya's was way better than Magus and Magus only really provided CDR and a powerspike, not nearly of a powerspike as a Zhonya's.
Honestly though, with the new AP items coming out, especially with Needlessly being cheaper and Rabs having a cheaper build path, AP junglers will do wonderfully with Runeglaive. Gives them a cheaper version of LB that all the actual mages scale well with.
Also, since I know it's going to be said... 'Oh, Runeglaive is so bad compared to Lichbane, there's a 20% ratio difference!' Yeah, well, Lichbane doesn't cost about 2300g, it costs 3k and most AP champions have to wait until their 3rd or 4th item before they can get a Lichbane since most need the 2nd item to be a big AP boost like a Luden's or a Rabadon's and then the 3rd sometimes has to be a Void if the enemies have MR, so you're stuck with a 4th item Lichbane powerspike rather than having it early on. Helps champions burst better early on, which helps most AP junglers.
3 of those guys are better with Cinderhulk, and 2 of those 3 still use Runeglaive quite well ( Cho with E, and Seju with W). Elise uses runeglaive VERY much so, so basically from your list, only Amumu and Fiddle don't use it. And with this, Fizz, Jax, Poppy and Ekko all can go ap in the jungle. Of those 4, 3 would go Devourer because they wanted on hit effects, that magus had none, and now they can go Ap.
