Any larger than 4 would need complete rebalancing of /all/ combat encounters in early access. If that was a prank, it was an expensive one
The killer argument is well known, as are counter-arguments, and that has been the case for a long time, not just yesterday or today... But precisely because of this, they could have been working on it quietly and secretly for quite a while.
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=672266#Post672266That being said, as explained in the thread, you can stick with a party of 4. But others would have the opportunity to increase their party.