If an effect causes a creature with changeling to lose all abilities, it will remain all creature types, even though it will no longer have changeling. This is because changeling applies before the effect that removes it.
05-02-2021
wotc
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.
05-02-2021
wotc
Changeling is a characteristic-defining ability. It functions in all zones, not only while a card that has it is on the battlefield.
05-02-2021
wotc
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.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.