I don't know, the CEO of Anthropic has openly said that each model by itself is profitable, they just reinvest everything into training more and more expensive models.
It just doesn't make sense to me that Opus 5 costs the exact same as Opus 4.8, my bet is that they simply subsidize Opus 5 more comparatively so it still looks as if they are making significant progress to keep investment dollars flowing, further inflating the bubble. I might be completely wrong but I trust nothing their CEO says, he's a habitual doom troll and will say whatever makes marketing sense.