I disagree — if you dig into the low propensity voter data, i would be very happy if I were a GOP operative with the red advantage on returned ballots for new voters and voters who only voted in 1-2 of the last four elections. OTOH, Ds solid with the high propensity voters early on.
1. The edge in 0x and 1x amounts to like 4K votes. It is unlikely to sway the election.
2. These things don't necessarily have trends. In 2020, remember that the Dems were WAY ahead on mail-in ballots in AZ, and then the GOP caught up with some late dropoffs. Plus, there are always random fluctuations in every data set. What we know is that the Pubs have a 4K edge over Dems in terms of returned ballots. That's all we know.
3. Again, the plurality of voters are (I). Their 0x and 1x turnout rate is low, but without knowing the composition, it's impossible to get an accurate picture. Consider this. Suppose there are 1000 0x I voters who return a ballot. They are all Dems. Then 500 GOP votes show up. Well, now the (I) turnout is increased, and it's still Dem leaning by a lot, so if you look at the topline numbers, that 500 votes looks like a good development for Dems but it wasn't.
4. We have no idea who the 0x voters are. If they haven't voted in the last 4 elections, there's no telling which party they currently support. They could be disaffected Never Trump Pubs who sat out elections and decided to show up this year because he's become a fucking lunatic, or because of 1/6.
5. Building on this point, AZ used to be quite conservative. It's only recently become purple. But AZ conservatism has been more libertarian than religious right historically. So a lot of those 0x or 1x GOPers could very well be libertarian-leaning -- which would explain why they sat out previous elections and maybe they are coming out to vote because they want to avoid the Trump tax.
6. Or maybe it's just that the GOP GOTV is working better right now. But there are so many unknowns that we really don't know. It's just not significant in and of itself.