Maybe. 
SPI devices are supposed to be high-impedance when their chip-select line is not active. Some don't do too well with that (e.g. the TLC5940). Some do. The datasheet sometimes spells out what the device does when chip-select is not active.
So, if the NRF24L01+ transceiver really does set its SPI pins to high-impedance then you are good-to-go.
However, in your schematic there is no pullup resistor on CE. If there is not a pullup somewhere on that line (e.g. internal to the NRF24L01+ transceiver) then you will have to add one.
Series resistors (220 ohm is a good choice) on the three SPI lines will protect all parties in the event of a mistake.