I doubt it. There is probably a reason why it has eight leads and not four, and the converter I have seen were boxes: not simply cables.
I think Fujitsu first had their own operating system on it, and only later made them MS-DOS and Windows-compatible.
Applications on the PCs with AT and PS/2 ports never interfaced the keyboard bus directly, but talked to a microcontroller on the system board, which had translated the AT/PS/2 scancodes into XT scancodes. I suspect that Fujitsu's hardware would have done something similar to make MS-DOS programs work.
