Any idea why they changed the title? Is it because they assume TV viewers must be ignorant, shit-eating chimps, when compared with the towering superhuman intellectuals who (supposedly) make up the R4 audience?
Frankly, if you're not going to understand the derivation of 'Bleak Expectations' then you're unlikely to enjoy the show anyway.
Certainly it's a far better title than the awful one they settled upon.