I believe there's about to zero percent chance of marines (even old men like garp or Sengoku) knowing the presence of Imu or the capabilities (like in this chapter) so it would be a big blow for them. Secondly Akainu's stance. What do you mean by this ? i don't think he's going to betray WG otherwise final war would be a big mess and we'll be seeing Akainu as good man amongst marines while he's someone who is definitely going to be an enemy of MC. Or with your stance you mean just getting away from WG and not participating in war (which again is quite unlikely to see).
The call will likely be tracked by Tensei, I think there’s a big chance the higher ups will eventually know.
I doubt even Fujitora will defect from the navy. Akainu is not dumb, he knows what Fujitora is up to but is still far too lenient with him, he talks shit to the gorosei and even tried to order them around, and he has a sword tattoo on his shoulder, not to mention a potential connection with Dragon. I think seeing his reaction provide some hints on his future role.