I didn't see this thread when it was first posted but will add a comment now.
Yes, acceleration will improve but not dramatically, the cost benefit doesn't stack up to put huge motors in a truck to make it perform like a car. The weight of the battery will more than offset any gains made by losing the ICE drivetrain, one of the problems Tesla has with its Semi is it weighing more than a normal prime mover meaning less allowable payload. Of course the Tesla Semi has a huge battery, reputably good for an 800 km loaded range and the Janus swappable battery is smaller (and lighter) than that so the weight penalty should not be as large.
If the heavy haulage industry can standardise their battery packs (and unfortunately it is unlikely to be driven by a little Australian company) then swappable batteries should work for trucks and other heavy machinery but if every manufacturer uses their own packs then it will just become too impractical.
