Not a BCCI fan nor a hater. BCCI has mentioned it has facilities in place and hence it does not require it to be part of the WADA as you also mentioned. I see no harm if the players be tested by government doping agency if that doping agency as you said is part of WADA as it has its accreditation. Its simple, in Mumbai most of the universities are affiliated and accredited by Mumbai University for education, students get a degree from Mumbai University but we study in different colleges and not Mumbai University.
Secondly, I do not think ICC has anywhere mentioned all countries must be dope tested by WADA. If ICC mentions that and BCCI does not follow then that is a breach of ICC laws. Correct me if I am wrong on this point.
As long as players are dope tested randomly every now and then, I do not see the fuzz around why it should be WADA or IWADA