Not the ix500, but I have an S1500 and SV600, and they both work for me after the upgrade to Mojave without driver updates or any other changes. I was just scanning some stuff yesterday.
Side note:
Interestingly, under High Sierra turning on the SV600 always triggered Micro Snitch to tell me my iMac's camera hardware had been activated, and since the SV600 is an open scanner I figured it was kind of "camera-like" and Micro Snitch was just confused, so I just ignored it.
But under Mojave I was explicitly asked if I wanted to give camera access to the ScanSnap driver, which I declined. And the scanning still works fine. So it apparently really did access the camera—no idea what that was about. I'm just glad to have Micro Snitch out of my face every time I'm using the SV600.