system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] Was Pippin's fuckup at the beginning of "The Return of the King" really necessary or else they wouldn't've seen the invasion of Gondor?

With how weakened Gondor was, and how Boromir's actions showed some level of desperation, wouldn't Gondor be the most likely place for Sauron to make a move next? He and his minion Saruman were already terribly defeated at Rohan, so the only pieces that Sauron had left to move were at Osgiliath and maybe his pirate friends from the south.
gpt
If you're referring to the palantír, and discussing only the film, then I'd guess the answer is yes. Gandalf thinks it fortunate that they've seen Sauron's plan, which suggests he'd have otherwise been somewhat unsure what exactly Sauron had planned.

In the books Pippin doesn't see the Minas Tirith in the palantír, he sees only Barad-dûr, the Nazgûl, and Sauron. Even before Pippin looks into the stone, Gandalf already knows Sauron will strike at Minas Tirith.