Good choice.
Full length mudguards if he doesn't want water spraying up his back everytime it rains (those ones that are half length or clip onto the frame / saddle stem are useless)
Marathon Plus puncture resistant tyres will reduce the number of flats he gets but they aren't cheap (its not fun fixing punctures in the dark / wet / cold)
Carry spare inner tubes, tyre levers, mini pump and know how to use them (I carry a bike multi tool and sometimes a chain tool as well but he can always walk if its only a few miles and something breaks)
Good lights, hi-vis vest, good lock, never used to wear a lid but got given one and got into the habbit of wearing it.
Change of clothes and shoes at work because at some point he will get soaked through even if he has high end water proof gear.
Nice to have:
Disc brakes - more consistant braking in the wet and you don't wear your rim away every time you brake which is good because new wheels are expensive!
Rear carrier and pannier bags depending on what he needs to take with him to work.
Not many people use them but think about getting a mirror (like the cateye ones) if riding on the road they do make a difference and I miss it when I ride a bike that doesn't have one.
Be aware of frost / black ice once winter kicks in, sometimes its just safer to leave the bike at home.
I thought there was a power and/or speed limitation before they became illegal.
Legal = 250w, pedal assist only i.e no throttle, above 15Mph motor must cut out; there was a consultation to increase power to 500w and allow throttles again but it died when the current gov were elected.
I've seen plenty of illegal bikes, scooters and even one bloke that passed my bike using electric roller skates; but the Police have random crack downs in different areas where they will confiscate illegal ebikes / scooters then they get crushed, rider can be prosecuted for no insurance, no licence etc and end up with points on their driving licence (even if they haven't got one yet).
Police take bikes away, arrest riders and people dont get their Pizza's:
Edit: they took the video down don't know why, anyway it showed a crackdown in Birmingham city centre but they have done the same in other cities.