What is the default behavior and appearance of an Exchange meeting request on IOS?

What is the default behavior and appearance of an Exchange meeting request
on IOS?

Does anyone know the "official" way an Exchange meeting request is
supposed to show up in a recipient's iOS mailbox? In my experience on
various Exchange environments, the meeting request appears as a regular
email with the meeting request's Notes in the body of the email, and a
single iCAL attachment (it also shows up in the iOS Calendar as tenative).
Only opening the Calendar entry or the attachment will show the rest of
the meeting details. I have taken this as the standard, however one of my
clients claims that they had received the meeting details in the body of
the email previously. (We migrated from ZeroLag to Office 365; hosted
Exchange 2007 to hosted Exchange 2013, respectively)