Not sure, I just checked the Bug Tracker and wasn't seeing anything specific that's a block.
Quite a few people are having trouble with the Afterburner not engaging, this is believed to be a problem with the game taking Keyboard inputs.
Saphir Radar is apparently having trouble operating to find and lock aircraft.
And there's a general post today on the ED Forums saying that it doesn't seem to work in 2.0.2, but there's no details and I haven't seen any official notice of it, though It wouldn't surprise me.
EDIT: Whoops, totally missed the 2.0.2 changelog, MiG-21 is apparently nonfunctional according to that.
To be honest I haven't been following DCS development that closely as I've been too busy in BMS.