machineelf
Explorer
The bolded part is not confirmed. Several spells they've spoiled (Command and Charm Person) have the ability to add targets by casting it as a higher level spell. If Hold Person has this, then a 9th Level spell slot could hit a 7 person party. Still not seeing an issue myself, but I wanted to clarify the point.
I think that's a good point, but even if they do allow hold person to hit the entire group at higher levels, some in the group might have proficiency saving throws against the spell, and so some (and not all, for this very reason) might resist. That would make for a fun fight against a powerful wizard, actually.