@ Lalli: having the house of Wittelsbach inherit most of the Austrian Lands would certainly help. Though there were more claimants, like the house of Wettin (Electoral Saxon branch), the house of Lorraine etc. and given the era some might just end up taking advance, whereas others will want to maintain a certain balance. Still once the dust settles after this ATL war of the Austrian Succession, Bavaria might end up with the bulk of the former Austrian Habsburg Lands, which, I fully agree, will give Bavaria the Powerbase needed for a more dominant role.
Now If the Wittelsbach would be able to keep Silesia, then the house of Hohenzollern (Prussia-Brandenburg branch) would already be weaker.