This syntax has been introduced in release 9 and in release 8 it was for further study (FFS).
We know that release 9 is an Introduction to LTE-Advanced i.e. also an Introduction to 8 x 8 MIMO.
So maximum 8 x 8 antennas is for downlink and 4 x 4 for uplink.
I think it is clear now that maximum 8 cell can report to E-NodeB for one radio bearers/ user.