That depends on the purpose of the orginal design.
You need to check if there is any conversion(I.E. chage of content by the PSOC) being done.
The PSoC is only doing "magic" to enable the 1:N connection, the two devices communicate fine in a 1:1 configuration (with direct connection.
If the SPI master can access multiple slaves (controlling the CS lines to the slaves itself), then you do not need the PSOC
If you only use one slave and talk to one slave, you don’t need the PSOC.
If you need PSOC to talk to multiple slaves and the master cannot control the CS lines, then there must be communication between the PSOC and the master to know which CS line to assert. If this true, directly connection the master to the slave means all messages to the “SLAVES” would go to that slave that is now directly connected to the master.
I realize that I have not written my statement very clearly:
I didn't understand completely your requirement. If you can put block diagram then it is helpful (now that you can paste pictures in forum posts).
Also, note that there are digital mulitplexers in PSoC. You can use those to multiplex lines between multiple SPI devices.