Yeah. Unless you already have a negotiation framework in place, it's probably a bad idea to announce how long you want to go on strike at the outset of a strike.
It's just signalling to the other side how long they have to wait you out.
I think if they said from the start it was indefinite Reddit Inc. Would have implemented plans to manually open them back up from the get go and no real splash would have been made. Saying 2 days reddit decided to sit back and wait, now the world is watching if they manually force subs open by replacing mods.