Is killing and replacing an entire party acceptable?

So, I am in the process of building a campaign for Dungeons and Dragons. My original thought for session 0 of this one was to have the players create characters they would want to play at around..say, 10th level, then force a TPK.
The main quest giver would summon the fabled heroes for their much needed assistance only to find that their children were instead summoned.

Would it be acceptable to kill off the entire party after creating weaker versions of their characters so the players still have the classes they’d like to play and springing the new sheets on them for session 1?
I am still fairly new to DMing so I am not entirely sure if I am above my position in doing so.