Codifying a 45-50 hour work week really doesn't help.
Putting it in writing up front for employees is crucial and good.
Further, an open expectation of 45-50 hours at a place that also encourages spending 4 of those hours on self-study seems fine compared to the risk-adjusted industry average.
Requesting is different from informing. "May I work from home tomorrow?" is not the same as "I am going to work from home tomorrow."
It seems reasonable to think this is codified this way because the alternative language of informing doesn't imply suggestion (b), but sure, it could also be due to the founders being control freaks.
In my experience, "you must ask for permission" is substantially different from "you don't have to ask, but your decision may be overruled". It sounds like your experience is different.
Perhaps the differences I see can be put into another context. Think about the action "eating off someone else's plate", rather than "working from home". Do you see the gap between informing and requesting in that circumstance? The difference seems huge to me.
I, like you, think that working so much will take too big a toll on your life, if you do it long term. But it could make sense short term, depending on you personal situation.
I think it's good that they're upfront about it, and gives me a general sense of confidence in the document. An employee applying for a job at Clef will be able to make an informed choice, which is great, because information scarcity makes taking a job a huge leap of faith...