Or on any other server at TBC release. The content is there if they want it.
This NEED to have a level 1 server is weird for me to understand. The only thing I can think of is that there are a group of players that want level 1 servers because they did not get the chance to do something in Classic, like get the AQ opening event/AQ mount, or become that AH god they aspired to be and want another chance.
There are several things that if you miss the opportunity when it comes, you do not ever get the opportunity again, so there is a big FOMO thing going on here and some players feel fresh level 1 only servers will give them that chance again.
But that is just my opinion so take it as you will.