No. The I3C CCCs are always preceded by I3C broadcast address 7’h7E. Since the I2C specification reserves address 7’h7E, no legacy I2C Slave will match the I3C broadcast address, and thus would not respond to the I3C commands. Likewise, the dynamic address assigned to I3C devices would not overlap the I2C static addresses, so they would not respond to any I3C address (even if they could see it).

FAQ Type: 
I3C