It is, yes, as the DeviceName property is not unique-valued within the directory. Here's an example from my tenant:
[13:05:29][O365]# Get-AzureADDevice -Filter "displayName eq 'New'"
ObjectId DeviceId DisplayName
-------- -------- -----------
ddc7604c-c242-4c0f-b81c-a721a700c9ee 02af79c7-ea0b-46e7-a5cc-5476b0ea3bc8 New
26ce1385-406c-4b4a-b55b-778191f23e16 d2503afc-5be6-4bb8-af13-38992c959cd4 NEW
In genera, you should aim to have unique names.