[tptacek]

Austin does not appear to have undergone a "net population exodus", at least not one visible on any of the charts I found (I stopped after FRED).

[wallst07]

I think you need to look at rate of change ( 1st derivative ), not net terms.

Meaning population increase slowed down relative to new housing builds. OP didn't say this, but it's what I assume.

[tptacek]

I think the claim made used both the word "net" and "exodus" and was simply false.