It appears that we need to wait some more time to see CST rate cut to 2% as per the news report available at https://economictimes.indiatimes.com. It says : -
"The government withdrew a statement on Friday about reducing the central sales tax (CST) rate to 2.0 percent on inter-state sale of goods from June 1.
The finance ministry said it would issue a revised press release on the sales tax later. It gave no time for the release and gave no details what the changes would be"