Yup, that’s a good point. That extra year with the birds rights was definitely an important part of Davis’ pushing for a trade. And I think even then the sign and trade eliminated that fifth year, I think that loophole was closed up by then. So the argument to do a sign in the trade in the off-season to retain BRs isn’t even a good one.
The only other angle one could take, would be to suggest that no matter what, Anthony Davis was going to get maxed out with Laker Bird Rights. They maxed out twilight Kobe, granted he’s a Laker legend. Hmm… KD had no problem getting a big deal after suffering a major injury in his early 30s, even having to sit a year. So there’s that.
I think ADs preference was the trade, clearly, but ultimately it all would have worked out for him anyway, but I understand him wanting the long-term security and sure thing.