So no matter what Germany ends up leaving Austria in almost all cases.
That is kind of disappointing.
Well, yes. There were major, major changes in circumstances between 1922 and 1938. To just list a few off the top of my head:
1. Rearmament, of course. Germany no longer had to be worried about conquest by friggin' Belgium if they stepped out of line. If Italy or Czechoslovakia decided to fight them over Austria, they'd have a decent chance of holding it.
2. The 1923 Ruhr occupation convinced France and especially Belgium that proactive vigilance wasn't a workable stance, and that they couldn't expect international support in pursuing it against Germany.
3. Italy had been split apart from Britain/France diplomatically by the Ethiopian war, so they were less inclined to block Germany to keep the West happy.
4. In 1934, Germany and Poland signed a non-aggression pact. Hitler was unusual among German politicians for his willingness to table the Danzig issue while he dealt with other concerns, co-opting the Poles for his own ends when he went to threaten the Czechs in 1938. Before that, there was too much bad blood between Poles and Germans over the Corridor and other land disputes.
5. The Little Entente started falling apart in the mid-30's, so basically none of Hitler's enemies were ready to present a unified front.
6. The re-militarization of the Rhineland in 1936 meant that even if France acted, they wouldn't have quite so easy a time of it.
I don't really consider myself an expert on these matters, so others could give you more details about all of this stuff, but the bottom line is that there was a lot of prior groundwork for the Anschluss to happen. Maybe 1918-1919 would pose a better chance, with everything so chaotic and fluid, but I'm skeptical of that, too.