And before it gets said, it wasn't for tanking purposes either.
It was the final trade to go down. The "tank" had already been secured. The presence of Varland for two more months, given what had already gone out the door, would not have had any meaningful effect on their lottery odds. Certainly not enough to forego a still-pre-arb bullpen option - who would've easily been the best remaining bullpen option in the organization - when they were now going to need those more than ever.
This trade was a fairly large bet on Rojas. That's it. In retrospect, it looks to me like Roden and France were there to balance the scales.
Also another indication that there's no intention to be competitive next year. The idea that it's wise to use their scarce free agent dollars (whatever that amount ends up being) on a market-rate high leverage reliever to replace a pre-arb one given the multitude of other areas of the roster needing an upgrade is bonkers.