My understanding is that the leaked ACMA blacklist was used as an example (even suggested as a preliminary actual list) of the sorts of things destined to be filtered by Conroy’s scheme. It was on this list that some sites (which were quite explicit) also had material on them related to genuine discussion about sexuality.
I think the issue at hand is that useful information is being blocked because it resides on sites that are blocked for other reasons. As such, I don’t think it will be affecting us.
That said, I’m completely against the filtering scheme. Anything like that should be opt-in (and well publicised), not mandatory. Conroy has already alluded to filter going beyond explicit material and on to censoring other things as well, and that puts us on the road to a China-style firewall. No-one wins there.