No, it will just take longer to get the best accuracy out of it if you don't....at $8-$10 a box, it makes more sense to have quality shooting sooner if you can.
Figure 150-300 rounds before the barrel is broke in if you don't lap it first.
Also, due to the rough bore, you'll get more copper fouling when it's new without the lapping, which affects accuracy, too.
Tim