I think we can look at Giratina and Deoxys at how they’re going to handle Black Kyurem and White Kyurem. They will likely be separate releases in raids and will likely have differing movesets to compliment them. For instance, Black Kyurem could have an Electric-type Charge Move along with an Ice-type and Dragon-type Charge Move in its movepool, while White Kyurem could have a Fire-type Charge Move alongside the Ice-type and Dragon-type Charge Moves.
Because of this, it looks like Gen 5 may have the longest release schedule of all the generations since they already have 9 Legendaries, and four of them have alternate forms. It’s possible that while we’re still over half-way through Gen 5’s Legendary release schedule that Gen 6 will be released. Gen 6 has very few Legendaries (only 3) so it may help balance it out.
EDIT: We talked about Conkeldurr’s moveset, and I had initially dismissed it learning Counter. I just learned that it can learn it through breeding in the core games. To my knowledge, Niantic has never gleaned from the Breeding movepool to get its moves. I’ll have to investigate each Pokemon and its moves in GO and compare it to the movepool from the core games to see. Might take a while.
EDIT2: GOT A HIT!! Pidgeot learns Brave Bird in Pokemon GO. In the core games, it can only get that through breeding in Ultra Sun and Ultra Moon! That’s enough for me! Niantic does in fact consider the breeding move pool for its moves. That means Counter is back on the table for Conkeldurr! I wish I could edit the original post to reflect that, but this changes everything! Even if Conkeldurr learned Low Kick instead of Counter, it’s still quite good as a rival to Machamp. If Conkeldurr learns Counter, it will easily surpass Machamp!