Loughton has 3 platforms?

Apart from during engineering weekends or emergencies the platform for Epping and Hainault is the same at Leytonstone. The other two platforms are westbound to allow trains from either of those lines to arrive at the station simultaneously.

So I wonder what the reason was to have a double platform.
Is that to allow interchanges perhaps?

Remember that when the Central Line was extended to Epping in September 1949, it had a very limited through service outside the peaks, and was supplemented by a two-car Loughton - Epping shuttle (which reversed either in the middle platform or the sidings), which improved the service intervals. According to the main timetable, the through services and shuttle services varied, and could each be, for example, every 48 mins, every 40 mins and every 36 minutes. There was a short period when the main service to Epping and the shuttle were each every 37½ mins - that didn't last long. Coincidentally, some notes about the Loughton - Epping shuttle will be in the August Underground News - so I am told

Of course, when the Central Line reached Loughton (and before Epping), the steam service used the centre track and platforms.