You are right that Import Policy was exploited by Importers, but it was Government and Custom Authorities which allowed to do so for more than 2 decades.
If government is real serious in making things right, it would have been done a better way. Things cannot be corrected overnight when it is shady since ages.
It would be better, if government had given an effective future date for the implementation of respective SROs,so that vehicles on port and in transit could get clearance and then make stringent policy to implement the rule they desire.
But unfortunately, the intention is malicious and the reason behind that is bribery by giant local manufacturer.
That's my point, others may not agree.