Yes, the current thinking is that depreciation over the 3 years will be about 68% on a fossil 2008, we have no real idea about the e2008 though but the last couple of years the secondhand EV market has completely changed and some EVs are barely depreciating as the demand is so high.
The current driving force for EVs is the BIK (benefit in kind) rate of taxation compared to fossils as EVs go from being a hobby interest to mainstream fleet vehicles.
A previous EV offering from Peugeot was the Ion, which is a cloned i-MiEV, and the Peugeot Ion depreciation was 53% over the 3 years, EVs have sinced moved on a couple of generations & are suddenly very popular.
Traditionally Peugeot have offered large discounts to fleet buyers, also to buyers of certain motoring organisations, so for instance I’d expect over £5,000 off RRP for a Peugeot 2008 GT Line 130 (a fossil), but I have no idea what discount is available on the e2008 (£3,975 off a R135 50kW Zoe though). These high discounts affect the depreciation massively if you base it upon RRP.
So, Motability are taking a risk, but no more than having lots of diesel cars on the Scheme 3 years ago, no-one living in cities really wants those diesel cars now. A real risk would be something like a Tesla Model 3 which barely depreciates currently, but in 3 years time if something goes wrong with the brand that could be a massive loss. Saying that, how many car brands can you think of with a car that’s left the Earth? Great marketing stunt.