Reading further into the detail of the announcement it also...

Reading further into the detail of the announcement it also advises that multiple drill holes failed to be completed in the drill campaign (for various reasons) which is disappointing and also the secondary drill assays didn't find anything of note.... so that could explain the more muted response.

@Arthur A I also get the feeling that mining underground at Mt Boppy has historically been a 'challenging' prospect, and with more climate events (eg flooding) likely to occur in the near term future that would increase further.
So if there isn't 'too' much dead dirt to shift (eg; the expanding the side walls of the pit) and it's economical I'd be in favour of expanding the existing open pit (to reduce complexity and risk of safety incident) to hit those juicy intercepts just below the current pit.