If I remember correctly, the first Arrowhead report came just...

If I remember correctly, the first Arrowhead report came just before the TPA when the SP suddenly got a big boost when shareholders believed that this was what SP we expected post the binding TPA.
I'm sure there were reasons then why it was considered necessary and the company probably signed up for a set of 6 monthly or yearly valuations for a set period of x many years which is why it still comes out but maybe the original necessity for this report is no longer valid and probably many, now no longer give that report much value.
Just checked the accuracy and yes the Arrowhead report and valuation came out 2 weeks before the announcement that the TPA has been given clearance to be signed in 2 weeks time. (quick, buy now ann)
http://www.asx.com.au/asxpdf/20151214/pdf/433rvk6p33qwwt.pdf
https://www.anzsecurities.co.nz/DirectTrade/dynamic/announcement.aspx?id=4031721