As far as Google has shown me, no post on this forum has pursued the electoral implications if Louis II survives in 1526. In short, the inevitability of Ferdinand's election is thrown into question.
Assuming Louis II survives the Battle of Mohács and retains his titles (King of Bohemia and Hungary-Croatia), what would happen in future Imperial elections? The Habsburg precedent to the Imperial title is still in it's infancy, and they lack an electoral title if Ferdinand doesn't inherit.
But Ferdinand and Louis are definitely close - both married to the other's siblings - and Bohemia-Hungary-Croatia's survival depends on German support to fight the Ottomans, so it's logical that the Habsburgs would buy Louis's vote with monetary or military support.
However, the Hungarian Jagellions are fairly tolerant of the Ultraquist/Hussite population in Bohemia, which would suggest that he is friendly to Lutheranism, and draw the less-than-Catholic electors.
Would a Habsburg emperor have the political capital necessary to create a title for the Habsburgs, either out of Austria or the Netherlands to buttress Habsburg power?
(In the timeline I am working on with a POD at the Battle of Pavia, Charles V has two sons and the younger gets the Netherlands; Louis II or his son will most likely inherit the Poland-Lithuanian crown when Sigismund II dies c. OTL)