It has been a very long time and this went through a lot of iterations, but yes I believe this is the only way to do it. Anyone without a glyph turns into a monster whenever they are outside a settlement or one of those little pockets of safety, so the options for moving people around are pretty limited without handing over the glyphs.
Generally speaking the idea was always for a new continent to be somewhat of a New Game+ that you could play infinitely forward. So it's not like you're starting at square one, but you also don't intentionally have every last thing you had built up on the prior continent.