Ann: Prospectus Closing Date Extended, page-3

Why? This is just procedure and as shown below taken from March 17 prospectus they have allowed for changing the date if needed see underlined below
Timetable
Action Date
Announcement of Acquisition and Appendix 3B 26 February 2021
Lodgement of Prospectus with the ASIC and ASX 17 March 2021
Opening Date of the Offer 17March 2021
Closing Date of the Offer* 7 April 2021
Issue of Shares under the Offer 9 April 2021
Expected date of Official Quotation of the Shares 12 April 2021
* The Directors reserve the right to bring forward or extend the Closing Date at any time after
the Opening Date without notice. As such, the date the Shares are expected to commence
trading on ASX may vary with any change in the Closing Date.