Yeah, I experienced with my Hotmail Exchange account earlier, Emails were not being pushed and I had to go into the Mailbox for it to find emails. This has never happened before, not once. So its definitely related to this update.
I haven't had an email to this account for a couple of hours so I'm not sure if its still occurring though.
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I just sent an email to myself on my Macbook to test if push works, as soon as it sent it appeared instantly on my iPhone, so I guess it works for me now.