You can roll off in software, sure.
However the results may vary from using the roll off on the mic itself. Especially if you use a compressor when tracking. those low frequencies can cause the compressor to cross threshold when it wouldn't have otherwise. So, if you later remove the low frequencies but the compressor is compressing it will sound strange.
Even if you don't use a comp when tracking, your preamp may overload more easily, and it also may react differently to the subsonic frequencies.
For example transformer saturation or harmonic frequencies that wouldn't exits without the subsonic frequencies.