Not sure about the actual mechanics of it, i.e.have they no means of communications now?.However, the new procedure only started when Ground moved from the "new" control tower back to the old one whilst refurbishments are ongoing for the next few months.
Only explanation I got from them one day was because "we're in the old tower at the moment"
Never saw a NOTAM but seems to be sid,stand squawk routine for the forseeable future!