That's the date teams can now speak with all pending free agents in the new CBA.
The days of showing up at midnight at players homes on 7/1 are long gone.
The rules make clear no one can be signed until 7/1 unless the team has the rights to that player.
If Snow wants to get his pick back for Boyle, and another team wants exclusive negotiating rights before 6/25, a trade has to be made realistically in a few days.
In short it's a trade for a nine day window now.