Haze...? I know it isn't everyone's WW, DT or Roar, but it's workable and not reflected by magic mirror (name preference). Anything with prankster and decent speed will also tear BP a new one, and while those are fairly specific, Prankster isn't exactly too much in OU, considering a few common pokes get it (Thunderous and Whim, mainly). The whole Taunt hitting through Subs is workable too. BPing to Espeon has the simple issue of needing to use a move, or lose any boosts, and prankster especially ruins that. With Volbeat, Idk how that will go, but they'd need it out constantly in order to counter its own ability, or else their team is screwed. If you let the team start up, then yeah, you're fairly screwed. However, BP teams aren't the sort of things that take losses well; each poke you take down weakens the chain to a varying degree. Also, drawing out the main threats right away (in this case, Espeon) before they get power is a big help. If they want to stop SR setup on the first turn for example, Espeon has to either be out, or switched to. Pick an obvious enough SR user, and Espeon can be hit hard early.
There may be some flaws in my logic, but as some people have stated, outside that one instance, Espeon isn't a major threat, MM or not. Espeon's actually one of the pokes who actually got something worthwhile from the DW, unlike, say, its Dark-typed brother. I'd personally hate to see that go, but personal opinions asside, if it's only an issue in something as isolated as a BP team, then remove it from that situation. SSwim was only broken on a drizzle team, and it was removed from that niche. In that case, a SSwim pokemon can still exploit an opponent's Drizzle, something that wouldn't be the case if MM was removed from BP. I understand the avoidance of complex bans, but I think a lot of us would rather have that than see Espeon AND Xatu lose MM (their main reason for being useful), lose BP altogether, or see Espeon thrown in Ubers (cringe). Simplicity can be useful and far easier to manage, but this case, like the SSwim/ Drizzle ban, would cost a bit too much unnecessarily. Every Gen will add more pokemon, more abilities, and more moves, so logically speaking, this process will never get easier, and the higher complexities will make it a lot harder to avoid complex bans in the future unless, say you want to see a ton of underpowered pokes in Ubers because we didn't feel like dealing with them in a more complex (and at the same time, simpler) manner. Results of this ban? The BP teams get a little stab... they lose what a lot of people are considering OP and voila. BP can still be used, Espeon and Xatu still have their niche, and not using BP on the same team as Espeon (or MM, Xatu probably wouldn't be used anyway) would only take out a few alternate options (like Espeon using BP).
