A: Yes.

(1) In webinar settings or attendee sidebar you can enable “hide muted attendees”. Since the guests would be muted in a webinar scenario, they disappear from the gallery (but are still listed in “attendees” list.

(2) in webinar settings you can enable “hide guest names and count from other guests” and remove the guest names from the attendees list (for other guests). Hosts can still see the full list