I don't know specifics, but I know on the south side (where the beaches are) that campground some people appear to tent camp, I don't think it's specific to RVs. I think the north side (near the paved entrance) is maybe RV specific? I've never camped in a designated spot so can't say, though I have a friend coming who got a RV spot reserved already. Their website says no primitive/beach camping, which matches what I see when i go in that the dedicated camping spots have people in them but no one is camping anywhere else.
I was hoping beach camping would be open by TH but it doesn't look that way. To make matters even more confusing, half the time on the weekends the main entrance is closed because the park is over capacity--which seems to be a COVID thing since it wasn't like this last year ever. The tunnel/offroad entrance is still open though, but if you don't have a reserved camping spot and you show up at like 1pm hoping to park in the staging area they'll turn you around. Multiple times this year we had to unload at the water towers, or take my Tundra with jet skis in the back all the way over to the tunnel entrance lol. And we have a park pass, so unless you have camping reservations they wont let you in regardless of what passes you seem to have. I doubt this will change for Trail Hero, but maybe Rich has worked something out. If the park is full and gets closed at 11am, I imagine it's gonna piss off a lot of people showing up, let alone if they don't know that camping is essentially totally restricted in the park right now.
TL;DR -- you can maybe get a tent camping site, but I would be surprised if they're not all booked. I would also expect to unload your rig outside of the park and drive it in through the tunnel (unless you get a reserved camping spot).