Looking at a couple other articles I gather that it was announced as open to the public? Another article mentioned that they have been working on the site for over 8 years: https://www.reuters.com/science/archaeologists-peru-unveil-3...

Archaeologists are excited for this find because it comes with a visitor's center and a parking lot.

Probably timed to coincide with the peak of the tourist season in Peru. Dry season is May-Oct (not at all advisable to visit Machu Picchu in the wet season). Jul-Aug is summer holidays for Europeans, who are the biggest cohort of international tourists in Peru (and summer holidays for North Americans). And Peru's independence day is 28 Jul, so locals take an (often extended) long weekend, so a bit of a spike in domestic tourism coming up too.