interface xe-0/0/0.2001 is present in OVSDB client but stuck in ADD Defer due to same issue of physical port being empty.
(gdb) p *(DBState *) 0x7f69f002c8f0
$4 = (OVSDB::VlanPortBindingEntry) {
  <OVSDB::OvsdbDBEntry> = {
    <KSyncDBEntry> = {
      <KSyncEntry> = {
        _vptr.KSyncEntry = 0xe22df0 <vtable for OVSDB::VlanPortBindingEntry+16>,
        static kInvalidIndex = 4294967295,
        node_ = <boost::intrusive_hook> parent = 0x7f6a2c3080a8 left = 0x0 right = 0x0,
        index_ = 4294967295,
        state_ = KSyncEntry::ADD_DEFER,
        refcount_ = (tbb::atomic) 2,
        seen_ = false,
        stale_ = false
      },
      <DBState> = {
        _vptr.DBState = 0xe22ec0 <vtable for OVSDB::VlanPortBindingEntry+224>
      },
      members of KSyncDBEntry:
      db_entry_ = 0x7f6a0010f9c0,
      dup_entry_list_ = empty std::list
    },
    <OVSDB::OvsdbEntryBase> = {
      _vptr.OvsdbEntryBase = 0xe22ee0 <vtable for OVSDB::VlanPortBindingEntry+256>,
      ack_event_ = KSyncEntry::ADD_CHANGE_REQ
    },
    members of OVSDB::OvsdbDBEntry:
    table_ = 0x7f69e000a020,
    ovs_entry_ = 0x0
  },
  members of OVSDB::VlanPortBindingEntry:
  logical_switch_ = (boost::intrusive_ptr<KSyncEntry>) 0x0,
  physical_port_ = (boost::intrusive_ptr<KSyncEntry>) 0x0,
  logical_switch_name_ = "aa91642d-1b0b-4527-8d9d-786a3fe0d692",
  physical_port_name_ = "",
  physical_device_name_ = "QFX1",
  vlan_ = 2001,
  vmi_uuid_ = (boost::uuids::uuid) fd8237aa-489e-41b6-bbc1-55537bfb8df6,
  old_logical_switch_name_ = ""
}


however for interface xe-0/0/2.2001 is missing from OVSDB introspect since there is no association of this logical interface to corresponding VMI, physical port or physical device
(gdb) p *(DBEntry *) 0x7f69e4016c30
$5 = (VlanLogicalInterface) {
  <LogicalInterface> = {
    <Interface> = {
      <AgentRefCount<Interface>> = {
        _vptr.AgentRefCount = 0xdffb10 <vtable for VlanLogicalInterface+16>,
        refcount_ = (tbb::atomic) 0
      },
      <AgentOperDBEntry> = {
        <AgentDBEntry> = {
          <DBEntry> = {
            <DBEntryBase> = {
              _vptr.DBEntryBase = 0xdffb90 <vtable for VlanLogicalInterface+144>,
              chg_list_ = <boost::intrusive_hook> next = 0x0 prev = 0x0,
              tpart_ = 0x7f6a2c0176f0,
              state_ = std::map with 1 elements = {
                [6] = 0x7f6a3883c8c0
              },
              flags = 0 '\000',
              onremoveq_ = (tbb::atomic) false,
              last_change_at_ = 1435893659364960
            },
            members of DBEntry:
            node_ = <boost::intrusive_hook> parent = 0x7f69dc3e84f0 left = 0x0 right = 0x0
          },
          members of AgentDBEntry:
          flags_ = 0 '\000'
        },
        members of AgentOperDBEntry:
        ifmap_node_state_ = (boost::intrusive_ptr<IFMapNodeState>) 0x7f69bc4f51e0
      },
      members of Interface:
      static kInvalidIndex = 4294967295,
      type_ = Interface::LOGICAL,
      uuid_ = (boost::uuids::uuid) cd823f4d-6ae9-49f5-a93b-cb749c72586d,
      name_ = "default-global-system-config:QFX1:xe-0/0/2:xe-0/0/2.2001",
      vrf_ = (boost::intrusive_ptr<VrfEntry>) 0x0,
      label_ = 4294967295,
      l2_label_ = 4294967295,
      ipv4_active_ = true,
      ipv6_active_ = false,
      l2_active_ = true,
      id_ = 1813,
      dhcp_enabled_ = true,
      dns_enabled_ = true,
      mac_ = 00:00:00:00:00:00,
      os_index_ = 4294967295,
      os_oper_state_ = true,
      admin_state_ = true,
      test_oper_state_ = true,
      flow_key_nh_ = (boost::intrusive_ptr<NextHop const>) 0x0,
      transport_ = Interface::TRANSPORT_INVALID,
      table_ = 0x0
    },
    members of LogicalInterface:
    display_name_ = "xe-0/0/2.2001",
    physical_interface_ = (boost::intrusive_ptr<Interface>) 0x0,
    vm_interface_ = (boost::intrusive_ptr<Interface>) 0x0,
    vm_uuid_ = (boost::uuids::uuid) 00000000-0000-0000-0000-000000000000,
    physical_device_ = (boost::intrusive_ptr<PhysicalDevice>) 0x0
  },  
  members of VlanLogicalInterface:
  vlan_ = 2001
}