The SFC was well alive and kicking when SFA2 came out (1996). I guess that Capcom took the installed base into consideration. Let's not forget that the SFC got Rockman & Forte in 1998.
It does feel rushed though. A few more weeks to improve the dead time when the SDD1 is decompresing the audio data just before the round starts and maybe incorporating the SA1 chip would have made a hell of a port.