It seems fishy to you to do a 50% storage improvement, when we just saw a 100% storage improvement to 128GB on the iPad?

Not fishy at all. Quite plausible. If anything, it's reasonably likely that there will be MORE of an improvement than the concept predicts, in this case.

That's a particularly odd configuration of flash chips, though. That's why you don't see 96GB SSDs very often. Generally, they're found in powers of two.

Its a marketing/pricing game. Manufacture all of them with 128G of storage. Every single one of them. Then the consumer gets to pay a varying amount to be permitted to use what they paid for.

This is a VERY old idea in the computing world.

Physical 128GB with 96GB user-accessible sounds plausible enough.

Honestly, that's the most realistic aspect of the whole concept.