Robert, I don't think you have ever agreed with anything I've posted, but the year is still young!
I would have bet that the first Warner Baxter title to hit Blu would be 42nd STREET. But as I posted, westerns, even those not featuring John Wayne, seem to do very well on DVD and Blu so my guess is that's why it's slated. If we start seeing more vintage westerns coming out it would probably lend more credence to the notion that came out this week regarding catalog titles and Blu possibly skewing toward older consumers. Most of the young people I know and talk to on a daily basis are not western fans, which strikes me as being very sad.
Actually, I agree with you more than you think, but I do disagree with your assertion about Blu-ray's acceptance with the general public.
As to In Old Arizona, IMO, I think Fox wanted to release a western in June as far as their marketing strategy. Why this particular title, only Fox can answer for sure, but I have some speculation on my part. First off, it's probably about timing more than anything else and what's ready right now for BD. Jesse James is upcoming later this year and I wouldn't want the sequel The Return of Frank James to come out beforehand. Secondly, other westerns like Brigham Young, Western Union, My Darling Clementine, The Ox-Bow Incident, Garden of Evil, The Gunfighter, Broken Arrow and etc. might be targeted for later releases or being farmed out to Twilight Time or Criterion.
Last Fall, I did have a conversation with Fox's main restoration guy Schawn Belston about My Darling Clementine. He gave me an impression that some more work needs to be done on My Darling Clementine before it's ready for BD. I did express to him that both versions need to be included in any further BD release. I think Fox is well aware of their "A" western classics that need to be released on BD.