The bouncing off a bamboo story is pretty entertaining honestly.
It's worth noting the Bradleys in American service have had their firing ports effectively plated over for decades. Bradleys were getting holed by .50 cal in the Gulf War and additional turret armor and armor "skirts" that covered the side firing points followed. There may or may not still be a firing point in the ramp but I doubt anyone still has the firing port weapons.
Most probably assume you were supposed to be able to slot the M16 or M4 into the firing port... But in actuality you needed the M231 firing port weapon. Higher rate of fire. No iron sights. Usually loaded with all tracers.
They were already an arms room oddity by the time I was with 3 ID in 2000.
All the new GEN IFVs (Puma, ASCOD/AJAX, CV90) have dropped the ports.
None of the newer wheeled APCs that I am aware of have them either.
Sidenote: The US Army should just buy CV90s. The ASCOD/Ajax is apparently a piece of shit (Or maybe just the UK version is. I'd like to hear the straight scoop from a UK service member). The Puma suffers from German engineering.
Will firing ports and/or doctrinally fighting from the vehicle NEVER return? I would be hesitant to say NEVER. The balance between armor and antiarmor weapons has shifted before. Could some radical shift in armor composition, active armor systems, or shielding make it practical to fight from the vehicle again in the future? Maybe. Or a NBC or nanobot covered battlefield may make dismounting instant death. Who knows.
So an APC and an IFV are pretty much used the same way these days. The only difference is the firepower and maybe armor they bring to the fight.
They both SHOULD dismount their Infantry well short of the objective/contact. The tracks whether APC or IFV can and should be used for fire support/the base of fire. Bare in mind an IFV should be able to provide effective fires from at least 1700 meters away (terrain dependent). (What is good in life? Killing your enemy while still out of range of their effective fires.)
In defense, some of the tracks weapons can be be dismounted and positioned on tripods. For instance the .50 cal from the M113 or the TOW from the Bradley.