Tamil Nadu Express - தங்களை அன்புடன் வரவேற்கிறது - Swaroop Kutti

Hey everyone! Need some advice here. Check it out - A dude books a seat on the 12420 Gomti Exp from New Delhi to Lucknow on the 25th of May. His status is GNWL 25. He then requests a vikalp transfer to the Shatabdi Express for the next day. Both the dates have available berths on the Shatabdi Express on the 26th and 27th of May. When the vikalp transfer is requested for the booked PNR, 2 days before, a similar case pops up for Tuesday boarding from Kanpur Central to New Delhi on the Gomti Exp whose vikalp transfer was to the Vande Bharat Exp. I heard that if there are empty berths, the PNR can be transferred under vikalp before the chart is prepared. Can anyone confirm this for me?