I don't know if they do for certain, but I don't think they would hesitate if you're an asset to the firm. PWC is a HUGE firm, hence the expenses are sky high and GC processing is a drop in the bucket for them. The only problem there, like javaguy mentioned, is that the timeline and patience required. With large firms comes layoffs if they need to cut expenses. PWC also has those ridiculous performance reviews which can lead to a firing. To be sure, ask during the phone interview if they would be willing to sponsor. Make it sound like you have growth strategy for a 5/10 year goal and to achieve it, you'll need a GC.
Good luck.