Sometimes their timing doesn't make much sense, as they try to space things a part so people always have something to maybe buy -- but that home should've been released with the new content.
I run into 0 bugs while going through the Preview, so what exactly is the hold-up with it? I haven't played it on PTS though (nor searched there..yet).
They don't usually release two new homes in the same month.
Let's not forget that Graymoor officially launched on consoles less than 10 days ago.They probably wanted to have people's attention on Proudspire for at least some time, rather than immediately releasing the Bastion too. The inn room and Proudspire should be enough to tide people over for a while.
They need to space their houses for the whole Quarter rather than dumping everything in the first month with nothing for the next 2 months until we see the next DLC content drop. Also, they were planning on holding the Midyear Mayhem event this month, so they are probably planning on returning an older house to the Crown Store too this month (Linchal would be my guess), as they usually do with their celebration events.