Hi Rahoolj,
I think what Matt was referring to with the 50 miler was to add in a 50 mile event 8 weeks out from your 100 miler. You would probably do a short taper and recovery from this event but can be a great confidence and fitness booster for the 100 mile race. Lets you try out race conditions and fueling etc. If not doing a 50 mile event and following the plan then 35 milers with consistency in your weekly mileage will build the fitness.
Leyla