Checked on QA  env and observed that it transforms "network_interface" for those hosts having "name" field contains an empty string or no "name" filed. Below are sample "network_interface" before and after uploading via foreman_rh_cloud plugin.
Env-QA-
case-1 -
'network_interfaces': [{'ipv4_addresses': [], 'ipv6_addresses': [], 'mac_address': '56:6f:0d:72:06:ae', 'name': ''}]
Result captured  from host profile -
'network_interfaces': []
 
Case-2-
'network_interfaces': [{'ipv4_addresses': [], 'ipv6_addresses': []}]
Result captured from host profile -
 'network_interfaces': []

Hence mark this bug as verified.

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 120 days