actually, not necessarily. I've replace torn (I mean really torn; no lube left inside) and were binding so bad, I couldn't turn left after a long drive with them almost binding completely...... Re-packed, installed original boot (not torn; clamp seal gone) on both sides (inner CVs; both) and that was in Jan..... No issues since. Re-packed torn outter CV boots several times (the outter tear more frequentll than inner CVs); no issues...... I will probably get my half-shafts rebuilt soon, but no issues after several re-packs of torn CV boots..... If the outter CV joints start to bind and clunk, then they're gone and need to be repalced, but if you catch them before, you shoudl be ok.
2009 335i Xdrive
JB4 and BimmerBoost Back-end flash
AA race FMIC and Diverter/Blow-off
& a few other goodies