Apple's huge bandwidth requirements could be for many reasons, but it's likely that they'll be pushing stuff into the exchanges rather than getting traffic from other sources. This is likely to improve Apple's download services (there's always big spikes in exchange traffic when say, Apple release a new version of MacOS X or iOS).
More likely it's to support Apple's new Apple Pay service that is coming to the UK in July (along with the latest version of iOS), supporting the alleged 250,000 merchants who are going to offer Apple Pay on it's release, means a lot of potential traffic back to Apple (though the wireless terminals will connect back to the merchant services servers such as Barclaycard), but mobile users paying for stuff in-apps/etc will go back to Apple.
Another reason for so much traffic is Apple's new streaming music service that launches soon (they want to replace Spotify) and streaming music does require LOTS of bandwidth.
After examining LONAP's member list, it seems the total bandwidth of all the members is around 630Mb/s (excluding content providers such as the BBC, Netflix, Google and Microsoft), so Apple's connectivity accounts for 25% of all their bandwidth. Google only have 40Gb/s, Microsoft 20Gb/s, BBC 20Mb/s and Netflix 30Gb/s.