BB8 will be quite righteous for droids.
With his taunt, counterattack, daze, tm gain, and heals, he fills the rolls of both K2S0 and Jawa Engineer, yet brings more to the table than both combined.
I totally foresee the new droid meta being HK, B2, BB, 88, R2. BB has a base speed of 162 which makes him wicked fast. He will be spreading that buff and taunting from the get go. Against CLS you could use R2's stealth, which shuffles things a bit, but would allow for plenty of AoE.
Against non-CLS teams we're looking at BB8 going followed by 4 characters each AoEing and having a single target follow up attack for a total of 24 criticals being scored. Now depending on who BB8 gives that buff too, his will be reduced anywhere from 14-18 turns. This means that in this team's opening zerg, BB8's ultimate ability will be reduced anywhere from 38-42 turns.
They can't AoE every turn, but there's still all the counterattack from BB8 to consider which is giving him ridiculous amounts of turns/turn meter, calling R2 to assist every time, and reducing his cooldown as well. I see it taking 3-4 droid rounds for this ability to come up, which will probably be over 10 BB8 turns, and is only around 2-3 rounds for most other teams.
BB8 is going to be very hard to get past as well. A 1 turn taunt on a no cooldown ability means buff wipes arent very helpful. Then he gives himself foresight whenever he takes damage and has all droid allies heal whenever he dodges.
That same no cooldown ability that makes him taunt is the one that spreads the buff. And it is self perpetuating, it's basically contagious. B2's basically the only one that can stop that buff from constantly being on all of the team.
BB8 stands a really good chance at making droids be actually viable again. He greatly expands the toolkit that they can have available on the field at one time.
Now this may be all in my head, but his ultimate ability vaguely reminds me of an idea that I had for a zeta for Lobot's leader ability and I wonder if they may have taken inspiration from it... But yeah, that's probably in my head.