That's why we encourage a new 1st-level character and once you start playing this series, you cannot play anything else with that PC until you find a way out of the demiplane. That makes it basically self-contained and separate for the for the season; sort of a mini-campaign.
No, I get that. I just feel that is not a good idea (IMHO) to try and add something along those lines -- with the whole Ravenloft/demiplane/trapped etc. -- in an already existing continuous open-format drop-in type of Organized Play campaign like AL currently is. It follows from the same arguments and concerns several of us had when the idea of Ravenloft was first brought up a month or two ago. I like the idea of a self-contained storyline, etc., but I don't like the idea of it being something that existing players can operate within. Had it been it's own, separate, self-contained bit, and not a 'season' with the gothic horror being shoehorned into the existing campaign, I would have been much less apprehensive about it.
Like I said, I'll hold off final judgement until I see the full Season 4 guidebook, etc., but I still have my concerns over the need to 'shoehorn' elements each season (such as 'madness' in Season 3, which I feel did not work properly at all) into the main campaign storyline here. A strict, tightly-constrained storyline -- while I love the idea -- does not work well with the sort of campaign AL is supposed to be -- by which I mean a 'hey, drop in when you can, don't worry about playing mods out of order, or if you can't make a session, etc.').
I love the idea of a tightly-connected storyline like this. In fact, I'd love to see more of these, but as a completely self-contained, standalone side offering of sort, and not as part of the main AL continuity. Gonna be messy for a lot of players, DMs and stores alike. For a lot of players with existing characters, Season 4 is just going to mean the AL campaign is 'on pause' for them until Season 5. Gonna be hard for a lot of players to come back from six-month absence.