Office365, FindConversation, ChangeKey="CQAAAA==" for all items??

Question

As the title suggest, see below a snippet for a conversation from the trace for "FindConversation" against Office365.
As you can see, the ChangeKey is "CQAAAA==" for all the items (across conversations), and interesting enough, it is the same as in the documentation for FindConversation
https://msdn.microsoft.com/en-us/library/office/ff406144(v=exchg.150).aspx
Is this a known issue?
<Conversation xmlns="http://schemas.microsoft.com/exchange/services/2006/types">
<ConversationId Id="AAQkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgAQAB2NeP3GTQlDp5B7AWesrrw=" />
<ConversationTopic>Kid's turning the dog green again</ConversationTopic>
<UniqueRecipients>
<String>John Smith</String>
</UniqueRecipients>
<GlobalUniqueRecipients>
<String>John Smith</String>
</GlobalUniqueRecipients>
<UniqueSenders>
<String>John Smith</String>
</UniqueSenders>
<GlobalUniqueSenders>
<String>John Smith</String>
</GlobalUniqueSenders>
<LastDeliveryTime>2014-11-26T16:21:37Z</LastDeliveryTime>
<GlobalLastDeliveryTime>2014-11-27T14:09:09Z</GlobalLastDeliveryTime>
<HasAttachments>false</HasAttachments>
<GlobalHasAttachments>false</GlobalHasAttachments>
<MessageCount>1</MessageCount>
<GlobalMessageCount>4</GlobalMessageCount>
<UnreadCount>0</UnreadCount>
<GlobalUnreadCount>0</GlobalUnreadCount>
<Size>16099</Size>
<GlobalSize>28992</GlobalSize>
<ItemClasses>
<ItemClass>IPM.Note</ItemClass>
</ItemClasses>
<GlobalItemClasses>
<ItemClass>IPM.Note</ItemClass>
</GlobalItemClasses>
<Importance>Normal</Importance>
<GlobalImportance>Normal</GlobalImportance>
<ItemIds>
<ItemId Id="AAMkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgBGAAAAAAC/m9YT3n+7RbfoU4MvIUlwBwDO121Po4OqQ7Wo59kdWfWgAAAAAAEMAADO121Po4OqQ7Wo59kdWfWgAAASN40cAAA=" ChangeKey="CQAAAA==" />
</ItemIds>
<GlobalItemIds>
<ItemId Id="AAMkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgBGAAAAAAC/m9YT3n+7RbfoU4MvIUlwBwDO121Po4OqQ7Wo59kdWfWgAAAAAAEJAADO121Po4OqQ7Wo59kdWfWgAAANAp25AAA=" ChangeKey="CQAAAA==" />
<ItemId Id="AAMkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgBGAAAAAAC/m9YT3n+7RbfoU4MvIUlwBwDO121Po4OqQ7Wo59kdWfWgAAAAAAEJAADO121Po4OqQ7Wo59kdWfWgAAANAp24AAA=" ChangeKey="CQAAAA==" />
<ItemId Id="AAMkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgBGAAAAAAC/m9YT3n+7RbfoU4MvIUlwBwDO121Po4OqQ7Wo59kdWfWgAAAAAAEJAADO121Po4OqQ7Wo59kdWfWgAAANAp23AAA=" ChangeKey="CQAAAA==" />
<ItemId Id="AAMkADMwZjkyMjExLTMzMGUtNGU5MS04OWIzLTAyY2ExYjM2ZjFiMgBGAAAAAAC/m9YT3n+7RbfoU4MvIUlwBwDO121Po4OqQ7Wo59kdWfWgAAAAAAEMAADO121Po4OqQ7Wo59kdWfWgAAASN40cAAA=" ChangeKey="CQAAAA==" />
</GlobalItemIds>
<LastModifiedTime>2014-12-05T19:12:48Z</LastModifiedTime>
<InstanceKey>AQAAAAAAAQABAAAADQKSGAAAAAA=</InstanceKey>
<HasIrm>false</HasIrm>
<GlobalHasIrm>false</GlobalHasIrm>
</Conversation>

Answer 1

It is a priority for my application that what I display to the user is consistent with the server.
If the user changed the item (change the IsRead flag for instance or other meta data), then that change must be reflected in the application without delay, when I pull the conversation. According to the changeKey, I know if I need to re-fetch the item.
It would be a shame if after I pull all the conversation and item ids, I would do a bind on items that did not really change just because the changeKey that I got in FindConversations is hardcoded. 
Now my target audience more corporate exchange servers, not as much as office365, so I could live with this bug but I need to know. Otherwise what is the point to send a ChangeKey if the value is guaranteed to be wrong?