Well, if you burn THEN cut a face, basic logic says that the resulting scar might be worse than just a cut. But it seriously shouldn't be anything dramatic.
As for being bad for the effects of laser, maybe..? I mean, they told me not to remove dead-fly-like hair residue or seemingly dead hairs myself, to wait for them to fall off on their own. (And I don't have the willpower to really comply to that, most of the time, sadly. :x) Because when you forcefully remove them, you might cause a bit of bleeding or a small wound/irritation which might stimulate the creation of blood vessels and actually end up reviving a dying follicle. So the cut, in the same way, might, very locally, revive a few follicles. But this is a possibility, not a fact, and it shouldn't have any major effect on the final outcome.