Uhh, if anyone's been paying attention to SCS or basically any other recent tournament it's pretty clear that there are so many ways to counter a metamidion. Many times it's the case that the team that doesn't bring the pyra wins nowadays. However, that's when it's a very well practiced team like Rydr or Spqr. I can see how newer teams might have a problem against metamidions but really I think the best way to progress as a team is knowing how to deal with different tactics, and that doesn't even mean you have to "lobby counter" but rather refine your play style to counter the other teams'.
In regards to pick order and banning, it makes me very nervous. Essentially, it would just further divide the skill gap in competitive as I see it. The only teams that would be so versatile as to not be affected by the ban are the top teams who have been playing the game forever. Newer teams will be forced to do things they're not comfortable with, and in the end it will just increase the chances of their failure. It seems to me that whoever made this ban thought that top teams only used metamidion or something, and this would put the top teams on par with the lower ones. However, that is simply not the case. Being on the Rydr team I can tell you we have practiced Mobula, Pyra, Junker, Galleon, Goldfish, and Lue even flew a squid at one point. SPQR have the same amount of versatility. Compare that with newer teams like Mad Hatters or WoD and it's clear that they have less room for things they are comfortable with. The thing is, as a new team starting out it makes perfectly legitimate sense to specialize because there is no way you'll be able to just get as much experience with every ship as the top teams. But if you specialize, you stand much more of a chance by having the same amount of experience with one ship.
As to the pick order? Meh. From what I can tell things just get more counter-y and I'm not a fan of the lobby counter game. You can implement it but I think it will just make people more wary of counters.