We may never know who the "unknown team" was, but I think it could've easily been the Vikings. And I think this trade had been in the works for weeks prior to the injury, prior to the draft.
GM relationship, Vikings waited to draft a WR, probably thinking their WR3 would be Hamilton. Former 4th rounder, good slot fit, perfect WR3, elite-level character.
So now what? Julio makes no sense. And there are no more free agents. I think the Vikings might be looking at another trade.
One player they might consider is Jamison Crowder, the Jets savvy slot receiver. 27 yo. Jets drafted Denzel MIms last year, brought in Corey Davis and Keelan Cole this year, and just drafted Elijah Moore in the 2nd round. We have a trade relationship with them from day 1 and Crowder used to play with Kirk Cousins in Washington.
With Crowder, the problem would be contract. Whereas Hamilton was on a rookie contract, Crowder is making about $9M a year. He might actually be released if we're patient.