Yeah, Heracross moving down to UU will certainly shake it up a bit, but I can't imagine it being as chaotic as when Cresselia and Porygon-Z moved down.
The UU players will probably be happy though. Pokemon leaving and joining the tier every few months is just part of the natural process of things if you play that tier.
The UU players will probably be happy though. Pokemon leaving and joining the tier every few months is just part of the natural process of things if you play that tier.