Wasnt it @California_Tanker who suggested that theres a case for Autoloader and 4 crew - (if not here then on his you tube account)
Something along the lines of - the 4th man can moniter APS / surveilance and help with maintenance yet the tank doesnt need the 4th to fight efectively and so 3 with auto loade if youve bodies either sick / injured or on holiday
Edited to add - he may also have argued it was potentially safer in that there wasnt an open door to the bustle (Abrahms) quite so often or for as long - but i wouldnt wabnt to put words in his mouth
Only insofar as there was no budget to create an entirely new turret which takes into account all the advantages of the autoloader, such as the decreased volume requirements making a lighter, tougher vehicle. I can think of no requirement which mandates that the fourth man be in the tank in combat. There is precedent: The US Army tried five-man crews for their M60s in the 1980s, for example, they were fantastic but the budgeteers shut it down, and the French have their extras run around in a VBL to play dismounted security when they're not involved in tank maintenance or whatever.
The case in point was the retrofit of the Meggitt autoloader system to the M1 tank. The ammo racks were replaced by a casette ammuntion stowage on the far side of the armored shield, leaving only a small hatch for the ammo to be fed out through, like in, say, Leclerc or K2. The autoloader itself basically replicated the actions of the human loader, taking the round from the rack, flipping it over, throwing it into the back of the breech. What the advantages are of that over a Leclerc style loader, I've no idea. Maybe it took up less ammo stowage room in the back. But either way, it was behind the breech and took up no space otherwise used by the fourth man.