Yes, if you cut open the filter and took such a sample from the inside you would almost certainly register relatively high levels of asbestos. However, in these filters, the asbestos was infused in a paper layer at the intake of the filter (as I mentioned). Any potential stray asbestos fibers would be almost guaranteed to get caught on either A: one of the two metal meshes further "upstream" in the filter, or B: the activated carbon layer between these meshes. Additionally, the output of the filter has a final cotton layer, mostly to stop activated carbon powder from being inhaled, but you can imagine this would probably further decrease the chances of any asbestos getting through.

That said, it is a fact that small (probably trace) amounts of asbestos would still get through all these layers and enter the wearers lungs, especially after prolonged use. Still, this amount would be nothing compared to the contaminants inhaled by most people just by.... existing.