I think they should find a balance between the bosses being hard by themselves and hard to figure out.
Something a lot of people most likely noticed about pretty much evry 3-D Zelda is that some of the bosses basically handed their weak point to you in their "dramatic intro" and ended up only having challange to offer some difficulty. Some had problems offering it, like Armogohma (well, I had some trouble with it, to be honest), whose eye inmediatly screams "Hit me!" to most people who had expirience with Zelda bosses. It lost some difficulty because of that.
I don't think the whole boss lineup was as easy as everybody says, at least not the bosses themdelves. Stallord was quite a challange for me, maybe because he shares a bit ALttP bosses, where you had to manage resources like magic carefully sometimes times and just be quick and observant in others. Figuring out was half the fight.
Personally, I would like something like the bosses in Majora's Mask, who had several ways to be defeated. Twinmold is my favorite example, you could use the Giant's Mask or rely mainly on your aim with the bow (my favorite way) and use fire/ice arrows, which also works pretty well. Both ways are hard to pull off, and it almost feels like a different fight with each (in my opinion).