Almost without a doubt.. You will still need new discs and pads, the seized calliper is not necessarily the cause of the warping, if they were shaking before under braking alone, but they are warped now so theres nothing you can do about it! even if you do free the calliper, it will still wobble under braking, so might as well swap them all while you have the callipers off.
I would partially agree with that. The minor wobble before could've been caused by the onset of the sticking. I have had some serious caliper issues on my GS, to the point where you could barely hold the steering wheel it was shaking so bad. Not to mention the smoke billowing from the front wheel when I stopped. As soon as the caliper was sorted, the vibration stopped instantly and braking returned to being super smooth.
On the subject of warped discs, which I'm not discounting in this case, it might be worth checking the torque on you lug nuts. If they have been over tightened (especially if you hve been in for balancing) then this could also cause some problems. My brakes can get a judder if they have been over tightened. Lexus cars seem hyper sensitive to this compared to anything else I have owned. I had new tyres fitted the week before last, only when the last wheel was being put back on did I spot what the fitters were doing. They were letting the air ratchet chug away for a good 10-15 seconds tightening up and then they were getting a two foot breaker bar and doing them up some more, :tsktsk: idiots. I could feel the judder driving home after a couple of miles. Undid and re-torqued everything once I got home. One wheel nut even broke my socket trying to undo it!! Considering they should be torqued to 76ft lbs, they must've done them to 3 or 4 times that. Worth checking.