Maybe -- sounds like your store liked to run lots of different events, benefiting players with a stable of characters who could then swap out from table to table depending on which table needed what character or what magic item might drop from the module on a given table. That's not a 'wrong' way to play -- there really isn't a 'wrong' way to play in that sense -- but it's not the style of play the storyline seasons were designed to support.
On the contrary, we have a very small pool of players to work with. We maybe have two players that can be there every Saturday, maybe another two that are
usually able to make it, and then another three or four that are pretty much random based on their schedules. Any others, when they appear, are random card gamers or college kids who try a game out once or twice, then move on -- usually because they do not like the particular structure of an Organized Play campaign. So most of our Saturday AL games are a toss up, assuming we get enough people. We don't have the luxury of a large gaming pool to pull from in our podunk town, and until just a few years ago, we didn't even
have a local gaming store since the last one had closed down some five years prior.
We have a large stable of characters, but that's out of
necessity, not intent or preference. We've played so many of the various AL mods so many times -- especially the various low-tier ones -- because we have such an erratic schedule, and that getting people together to play a specific mod that someone needs means the rest of us often have to make new PCs to accompany them so we can have a legal table.
Unfortunately, with the 'no exit' approach to Season 4, we cannot operate with that back-and-forth option. If we have a new player who drops in and would like to play some S4, then we need to create new characters to accompany him -- we can't just bring in a pre-existing one from our 'stable' as we could in seasons prior. That's okay in and of itself, as wer'e used to making new characters over and over again, but the real problem is if some of us end up missing the 'exit' mod from the season, due to our erratic schedules. Presumably that's near (or at the end), which means a higher-level adventure, which means we're unlikely to want to pull an established higher-level character -- that you've put two years of work into -- in for a random game in Season 4 if they can't be guaranteed a way out.
I understand the idea of the Mists and the 'locked' aspect in an 'Encounters' run, or a hardback campaign, but not in the
regular season of an Organized Play campaign. And while I agree with you that there is no one way to play, there are certain defining characteristics of an Organized Play campaign of this type to begin with, and the the lack of a
required linear play order is one of those immutable pilars upon which OP is supposed to be built upon, specifically because Organized Play is
defined by its 'play wherever, whenever' approach. Which is something that Season 4's lockout aspect goes directly against.
But all of this is largely moot; people have brought this concern to the staff since before Season 4 was announced, when people were thought-experimenting on how the Mists might work in an Organized Play setup. I still hold out hope that when Season 4 actually gets here, there will be some sort of allowance made for people who are unable, through no fault of their own, to play the restrictive exit mods(s), so they do not have to potentially just write off that character.
Maybe an expensive time unit payment to get out? I don't know, but unless something like that is in place, at least for our local group, we'll be doing far less AL in Season 4 that we ever have in the previous three.
