Previously, it was possible to set a path to the speciefic place for a zombie using invisible villagers, which are not visible for players but for zombies.
Another one example of drawback is invisible illagers with a custom model on their heads. Having them in different team could make them fight each other. And now it's impossible because of the recent invisibility potion fix.
As a mapmaker it blocks me to create new original content. My suggestion would be to add some kind of an NBT tag or a status effect namely "clairvoyance" or something — which obviously allowed to see invisible entities.