I never said it couldn't have been from Germanics directly, but rather that it is possible for some subclades to have arrived with Slavs in the Albanians. Possible doesn't mean that it couldn't have been otherwise.
An example is: I-Y16436 on FTDNA or on YFull:
https://www.yfull.com/tree/I-Y16440/
The Albanian while numerous subclade is extremely shallow. Upstream are a Belorussian and there is a parallel, more diverse/older branch with Serbians/Croats: I-Y16434 (FTDNA)
That's a case where we have just Slavs upstream and parallel in the crucial times - so far. Any new samples could change that and I can hardly say it definitely came with Slavic speaking people. Its just possible to likely. The Albanian subclade split about 500-800 years ago. From the South Slavs they split about 400-700 AD, which means it could have been both. From the Belorussian this Balkan group split much, much earlier and otherwise there are just no samples I know of.
If the Serbian/Croatian samples would themselves be of Vlach/Albanian descent, that would be something in favour of an older local Germanic origin instead of a later Slavic arrival.