[Spoiler] Are 3 (optional?) minibosses missable?

[banz99]

Don't read this if you haven't come across the Axom quests yet.

So I defeated the Visage Axom (Mask Keeper) by actually listening to the taunt and going straight to the fight. Now I've come back and Seething Boucheclier, Jovial Moissonneuse and Sorrowful Chapelier are laying on the ground lifeless, I can't interact with them, and more importantly I can't get their dropped weapons. :/

[Abelardo]

I'm on basically the same boat... came here looking for a way to get the drops... =(, apparently, we're out of luck.

[Lily Valesti]

New Game Plus is your friend. Or, not... considering the increased health pools and damage. But yes, you missed them this time.

[Amritadyne]

the game has missables, toke note of what you missed and don't miss them in NG+

[[$$$] Swarm & Scrap Solutions]

This is bad game design.

[Bizarre Lad]

Are those the mask bosses with the joy, sadness and anger emotions? If yes, then I think they might be dead because you killed Visage, Visage was keeping those masks alive (haven't confirmed this, but this seems like the case).