They claim there’s a technical reason instead of a financial one:
"Snowdrop relies heavily on disk streaming for its open world environments, and we found the Switch 2 cards simply didn’t give the performance we needed at the quality target we were going for. I don’t recall the cost of the cards ever entering the discussion - probably because it was moot.
“I think if we’d designed a game for Switch 2 from the ground up it might have been different. As it was, we’d build a game around the SSDs of the initial target platforms, and then the Switch 2 came along a while later. In this case I think our leadership made the right call.”
No explanation was given as to why they didn’t forgo the key card altogether and just release to the eshop only.
It’s probably not hot air in terms of what GKCs will mean for the future, but casual audiences most likely do not care as much, or maybe even know, as the perpetually online. See as well the Switch 2 boycott which didn’t really mean much for Nintendo. I say all this as someone that is not currently purchasing from Nintendo, as well.