Not sure what thing exactly regarding Smoker...
However, the reason why I think Smoker isnt here is to save him up for later, oda probably doesnt want to reveal his gains yet.
Also, I think that BBPs will let Coby and Tashigi go now that they have a far better bargaining chip - Garp the Hero.
Smoker and the gang coming in to rescue Garp or Tashigi and Coby if they dont let them go is probably unlikely.
The plotline of Blackbeard's bargain has to pay off, imo. World Government accepting Beehive as a new kingdom and stuff...
Which is probably just another plan of Blackbeard to sneak into Mariejois.
Smoker should play a big role in that event when Blackbeard starts revealing his true plan.
I really doubt he will jump into Beehive like Garp did, there isnt much he can achieve there with all the big shots around.
Also, I am reasonable about Zori too, people just need a couple of years to agree with my takes.