Ann: Project Update - Georgia Lime Project, USA, page-4

You would think if they weren't going to proceed they would know by now and not need another extension.

If that's the case, the extension must be to finalize the sale of Georgia Lime which they had reasonably expected might be completed by end of TH and isn't.
From there, the 'in parallel' acquisition is partially/wholly dependent on the sale completing. Perhaps financially, mitigating the need for an immediate raise for the acquisition?

These guys are very focused. I just don't see them running a lime quarry in parallel with an acquisition unless the two are somehow complementary.

Just speculation.