Littjara Kinseekers

If an effect causes a creature with changeling to become a new creature type, it will be only that new creature type. It will still have changeling; the effect making it all creature types will simply be overwritten.

If you don’t control three or more creatures that share a creature type immediately after Littjara Kinseekers enters the battlefield, its ability doesn’t trigger. If you don’t control three or more as the ability resolves, you won’t put a +1/+1 counter on Littjara Kinseekers or scry 1. The three shared-type creatures you control when the ability resolves don’t have to be the same three you controlled when the ability triggered.

The subtype Shapeshifter that appears on the type line is mostly there to reinforce the flavor. A creature card with changeling is just as much an Elf, a Dwarf, a Sliver, a Goat, a Coward, and a Zombie as it is a Shapeshifter.