Luckily, IRCC has now come to senses to allow IMM 5669 (and police check) to be included with the initial application package to be mailed out (effective Feb. 14, 2018).
IMM 5669 form request has been, and still is, one of the many jokes of IRCC: there are different versions concurrently in use, and different CPCs (sometimes the same CPC or VO) will send you different requirements. Good luck guys!