I've read that people ran into an issue with this because it fills up their inventory with items that you can't get rid of. Is this still the case? Should I buy the pack on a random alt or something before I create my main character?
There are a total of 19 maps contained in 4 boxes. You can bank the maps but not the boxes. I would get them on an alt to hold the boxes and pull out single maps as you need them.
Must be the maps you're talking about. They came in containers when I got it way back at launch, not sure how it works from the crown store.
If it's still containers, then yes, they'll take up bag space as you cannot deposit them into your bank. If it's straight maps, then yeah, there's a lot of em.
If you don't want the maps it won't matter what character has em as you can just delete em all. If you want em however you can shuffle em between alts, they are bankable.