It is like every now and then a Googler has to say Google never had any Sandbox algorithm. They said it as recently in December. The Google Sandbox concept dates back to 2004. However, many SEOs felt there still was a Google Sandbox. In fact, just a couple years ago, many thought there was a Google Sandbox 2.0 but that conversation died down a lot.
However in 2005, Google's Matt Cutts said there is something like a sandbox. There was even a hack that worked to see sites pop out of the sandbox, it really did work back then.
But Gary Illyes posted on Twitter:
@alejandronovoag We don't have a sandbox
— Gary Illyes ᕕ( ᐛ )ᕗ (@methode) May 25, 2017
I am sure Google never called it a Sandbox which is why Google can deny it.
Forum discussion at Twitter.