That would all depend on how warped they are & where they are warped. If it has a knot in the forestock, that could always be a issue. IMHO.
I seldom buy a precarve any more, as have had several instances of stock issues with them being warped too bad or bad grain at the wrist, or being over-inlet, & am not dealing with that any more. Easier to hand pick my own stock blanks & send a blank to a friend & have the barrel inlet & RR hole drilled & do my own thing. Yes, it cost me more, but this way I know I am starting with good quality & what I want. But if I do buy a precarved one, I get the barrel too & soon as I get home I inlet the barrel & wrap it up TIGHT, so it cannot warp.
Couple things I will mention. If a stock is precarved or preshaped & then set aside, most likely the forestock will warp to some extent, as it will take moisture or dry out more & it is going to warp. If the barrel is kept in it & it is wrapped tight, it usually will not warp. These places with hundreds of stocks in inventory, cannot afford to put a barrel in each stock just for you.... So some of them are going to be warped.
All of the stocks I have in my shop have the barrels inlet & they are wrapped up TIGHT on the forestocks, waiting on me. They also have the bores greased with RIG and they are plugged at the muzzle with RIG and same on the breech, with Saran Wrap on both ends to keep the RIG from getting into the wood. This has worked well for me for years.
I also have wet warped stocks, put a barrel in them, wrapped them up tight with rubber tubing, a month later take them out & they be perfectly straight. Build the rifle, slim it down, seal it inside & out, has not been a problem. Several times have bought one with a bow in the middle or bowing down at the muzzle. This is usually not an issue to pull straight. When you get grain going 11 dif ways & knots, this could be an real issue. I am also reluctant to buy one that is curved several ways or twisted on the forestock unless it be Very very slightly. The twisted ones can be a PITA.
Other builders see it differently & at times a challenge to make... one work, I choose to nip that in the bud & start off without those issues to deal with.
Keith Lisle