I don't know of any other changes that would affect these settings, so I imagine there may have been some content things. Hard to know as I'm not actively working on Fortnite stuff currently.Performance on medium virtual shadows is not the same as before on the same settings but noticeably lower even though the virtual shadows for grass and debri are, as intended for medium settings, not rendering.
It will depend a lot on the specific case, view and system. Likely the cases where you are most likely to notice a difference are on lower end GPUs when directly inside tree foliage (due to resolution differences). Possibly also some differences in scenes with many large local lights present (some of the warehouses or castle views, but you have to know what you are looking for). That said I do not expect the differences to be large here, and without a proper way to replay a frame by frame capture you're not going to be able to weed out stuff like a couple hundred microseconds in specific sequences from the noise I imagine.Performance does not change between medium and high virtual shadows.
That said, as discussed in the other thread, it's pretty common for certain settings on PC to not have large performance impacts in specific view/GPU combinations. That's just the nature of the beast. If it doesn't affect performance much on your system, set it to high and enjoy