There is 27 222s (23 5-cars and 4 7-cars), with a total seat capacity of:
7-cars: 236 standard and 106 first class seats:342 seats per train, 1368 seats total in fleet
5-cars: 192 standard and 50 first class seats:242 seats per train, 5566 steats total in feet
Across the whole 222 fleet, there are therefore 6,934 seats
There will be 33 810s, all 5 car
they will have 254 standard and 47 first class seats, giving 301 seats per train, or 9,933 across the fleet
In short, there will be an uplift from 6,934 seats across the fleet to 9,933 seats, so about 3,000 extra seats, both by having more trains and more seats per train. If that doesn't qualify as a capacity uplift I don't know what does!