Hello,
Port-mirror is supported on MX960 with any DPC and MPC card.
MPC10 is not a prerequisite, any other MPC supports port-mirroring.
Port-mirror is also supported on MX fixed chassis models (without DPC or MPC card) such as MX5...MX80.
Please click on "Feedback" tab on the right to submit Your concerns to Juniper Tech Pubs team.
HTH
Thx
Alex