I suppose you'll get these games quite ugly looking without bilinear, especially KOF
because they reuse characters sprites from Neo-Geo games, which had different pixel aspect ratio, so sprites are non-integer scaled in AW/NAOMI games, and use BF to make artifacts less notable.
same thing with Capcom games btw.
PS: if you see some sprites blurry - this means there used some fractional scaling. if sprites will be rendered with integer scaling, 1x 2x 3x etc - there will be no any visual difference with bilinear filtering or without it (point sampling), sprites will look crisp clear in any way.