Wonder if they should remove the Ymir Flesh requirement from the Iron Sledge. The Iron Sledge is already decently annoying to craft requiring a Draugr Elite trophy which isn't necessarily a common drop. Dropping the Ymir Flesh requirement would allow you to craft the Sledge if you could/wanted to while continuing to lock the Frostner behind Bonemass.

I do think the potential to have crafted a Frostner to fight Bonemass with is probably the primary reason for the change. Bonemass is weak to blunt damage, susceptible to Spirit Damage, and is always Wet which in theory allows Cold damage to do more to him. The Frostner takes advantage of all three of those weaknesses. Assuming you can locate Silver Veins without using the Wishbone.