I think people are mistaking. The sealing jutsu Preta absorb in-coming attacks. So what i mean is that, if an attack touches the user before he activates Preeta, he can't absorb it. That's why Madaras clone weren't able to absorb th last Jinton attack made by Onoki before protecting himself after with Perfect Susanoo. He said himself that cuz the clones were protected by Susanoo, he didn't had time to use Preta to absorb it. It's also the reason why Nagato couldn't absorb Amaterasu. There is a radius were the jutsu is activated and that help to absorb all ninjutsus.
Also, people believe that Preta absorb every type of ninjutsus, which is somehow true, but what they failed to realise is that Preta is not absorbing the ninjutsu itself, but it absorbs the chakra used in the ninjutsu, and that's why the jutsu vanished.
So for people saying that Preta could absorb things like Mokuton, or Madaras meteor, or even doton techniques, it's wrong, cuz eventhough it's a ninjutsu, it creates solid material in a large scale, so Preta would have difficulties to absorb the chakra in the technique. And at that time, the user will receive the damage of the solid/physical technique
That's why Preta would be useless against such techniques, at least it's what i think