I doubt it. It's probably just because it doesn't make sense in any game for a group to buy 8 seals; 4 is enough.
There are some cards it just doesn't make sense to buy in bulk; Bamboozle is another one, although now that it works with any villager and not just infiltrator it does arguably make sense to get more than one, although I can't see a situation where any group would want all 6.
Yeah, I think one Bamboozzle is usually all you'll need (for the whole party), though you could possibly put two to good use a considerable fraction of the time, if you don't go for building lots of Walls. Still, I think a second Bamboozle would rarely be worthwhile (even though the first one is probably the single most worthwhile Skill you can buy in most games).