I don't know all the ins and outs of it ( the scientific stuff ) but if you had an illness that was terminal and you got frozen BEFORE it killed you, I could possibly envisage that working.........but waiting until AFTER you died.....MMMMmm.  They wouldn't just need to thaw you out to a degree where everything worked perfectly, but they'd be raising the dead as well........a step too far perhaps ?  We won't even bother going into what potential living hell on earth could be confronting you, in perhaps 200 years time, when you were brought back.