Not to any major extent, because the majority of the Reading capacity improvement is on the mains, with 5 through platforms where there were previously 2.
On the relief side, the main improvement is that rather than having two London facing short bays there are two central through platforms, between the up and down reliefs, mainly used for terminating trains from either direction. Stick a ten car terminating Crossrail train in each and the 'extra capacity' is full.
I've said before now that even though Reading can clearly now cope with a few 10 car terminating trains per hour using the reliefs to/from the London direction, that is not quite the same as there being loads of Crossrail specific infrastructure, as is sometimes assumed.
