Most certainly. It would be unwise to think otherwise. Plus it depends from region to region.
Say Malesia tribes, if you look at YDNA <=3% are Slavic. But overall in Albanian speaking communities they fluctuate 8%-20% depending on region. So you have places with more intermixing, and virtually hermetic regions, geography and history plays a role here.
Furthermore given the ethnogenesis of Albanian as an ethnos around 1400's (most western schools would have you believe that the first nations/nation states were created in Western Europe around the 100 year war, them being France and England, so its a controversial topic, but lets take 1400's knowing the history of our region, which they might have understudied), before that from the bronze age we have around 3000 years, and 600 years since then, so it is reasonable to assume further intermixing during these eras.
My point with that larper was different, and watch him be unable to produce any source or evidence for what he claims. I know Slavic Macedonian members on fora who only score 20% Slavic, while their group of friends the highest is 30-40%, but he would have us believe Albanians are 33% pure Slavs, whatever pure Slavs even means, since most Slavic members on fora can not seem to agree, and its a hotly debated topic.
If it was not so funny, the larper would be cringe.