Magyar Nationalism aside, Pozsony became a part of Austria in 1301 within a decade of Rudolph I's death, and Austria's spawn is currently linked to Rudolph's reign. Also, Pressburg was not taken as the result of warfare, but was inherited by the Austrians. I'm aware that Sigismund brought Pozsony back into the Hungarian fold, but after his death Pressburg was firmly Austrian. Also, AI Austria is in desperate need of a buff and it needs to be more antagonistic against Hungary.
Yeah, sry if I sounded harsh, but I can't imagine it flipping. As I said, conquering the city may be OK, but nothing more
I don't know what you are referring to, anyway the game cannot illustrate the exact political relations of Rudolph, Ottokar, and the Hungarian kings...
Either of us knows something wrong, but Pozsony was hungarian all along (except for a few years maybe?). III. András granted town priviliges to the city in 1291, a few years after Rudolph's reign ended

Zsigmond (Sigismund) just granted free royal town status in 1405, I don't really know from where he should have brought it back?
Also, while Pressburg always had some german population, it was never firmly austrian (actually, not even slightly

). Neither before, nor after Zsigmond's death
EDIT: Btw, 1301-1308 was interregnum in Hungary (after the Arpad-dinasty died), so even if Pozsony was at Habsburg hands for a year or two on paper (but I don't even find anything on this), it has nothing to do with the rising power of the Habsburgs, rather the failing central rule in Hungary (stability issues in the mod)
And there was certainly nothing like "inherited by the Austrians", or "became a part of Austria", not even in name
EDIT2: I just spent more than an hour from my modding time on reading everything I find about this
