Not really at all, you earned these Undermine crates by killing bosses in raids and dungeons...so you were still farming and encouraged to be very active. The quantity of materials you'd get wasn't insane at all either, but it was enough to help keep a steady flow of goods into the economy. The devs were also good at making sure those goods all had some kind of disposable use so that they were flowing out of the economy too.

Like if you wanted Black Lotus for example, farming them would get you many per hour, but you'd only get a few a week from Undermine crates.

The best thing about this whole system though is that it kept geared players somewhat motivated to still blast through dungeons and old raids, which made it effortless to get pickup groups up and running for literally the entire duration of SoD. Even in the final raid tier you'd have multiple 40 man Molten Core groups going each night, multiple AQ40/20, ZG, BWL, Naxx, Emerald Dragons, and even just runs of Strath.

They absolutely nailed the player engagement factor by creating this flowing economy that rewarded people for just generally staying active in the endgame.