I don't really agree with this perspective. Granted, while this would've almost certainly been true had Hillary divorced him back when they were still in AR, as her rise to national prominence came alongside Bill's in 1992, she was already well-known enough by the time of Monicagate that divorcing him at that point in time would've made no difference, & - provided that she's still interested, as she presumably would've been, given the later trajectory of her real-life career - NY's Democratic machine would've ensured that NY-SEN 2000 is still hers so long as the then-popular Rudy remains a candidate, as he presumably would've through his cancer diagnosis in spring 2000, & by then, Hillary - as real life proved - obviously wasn't gonna be dropping out in favor of somebody like Lowey just because her services for what had previously been a presumed match-up against Rudy were no longer needed. And at worst, the sympathy vote that she would've gained by virtue of being the aggrieved party in the divorce would've made up for whatever influence she would've lost due to losing Bill's connections, which would've been minimal nonetheless, given not only that she had connections of her own but that a divorce doesn't reasonably preclude her from accessing connections that'd be sufficient to win. All of which is to say that I believe that Hillary would've still been a Senator on Jan. 3rd, 2001, regardless of what had gone down with Bill.
In any event, had Hillary opted to divorce Bill after the news of Monicagate broke, his presidency probably would've been finished anyway & we'd likely get the 2nd presidential resignation from office in American history. Obviously, this happening would've established true-incumbency for Gore in 2000, which would've been an interesting butterfly, to say the least.