It is a bit insidious that the price hike coincide with the end of 2x promotion, which makes the usage change a bit more obscure.
The fuzziness is intentional. It gives them wiggle room and obscures how much "value" you actually get from $200, a 5-hour block, or a week. That keeps the tension manageable between subscription pricing and pay-per-token API pricing, especially for larger businesses on enterprise plans who want transparent $-per-MTok rates.
If they were fully transparent, like "your $200 sub gets you up to $2,000 of equivalent API usage," it would be a constant fight. People would track pennies and scream any time 5-hour blocks got throttled during peak hours. Businesses would push harder for pay-per-token discounts seeing that juicy $200 sub value.