There has been some confusion that Argoth, the site of the Sylex explosion, later turned into Yavimaya. I think that is inaccurate, but the argoth wiki article explains a bit more. Could this be what you are thinking of?
Disputes over location
With the release of Future Sight, Yavimaya was mentioned as being located where Argoth once stood. This has led to some confusion with readers, due to the fact that this information hasn't been given prior to the book and that Yavimaya has another fixed location on several maps of Dominaria. The release of the official map in 2018 confirmed that the main part of Yavimaya was still in its original location, northwest of the Shattered Isles. It is now a separate island, while a small remnant is transplanted to Urborg.
I know issue 40 of duelist magazine talked about this as well, so maybe you read that?
Urza was captured in Yavimaya for a while before the phyrexian invasion, I don't know which book that occurred in, or if it specifically mentioned a hollow, but that is probably what the card represents.