The advancements "Is it a bird?" and "Is it a balloon?" can still be unlocked even if the mob is invisible. This might be intended, my dear. Since you cannot see the mob, you aren't truly observing it. Please note that you cannot make the ender dragon invisible due to MC-82046. Consequently, you cannot test it for the "Is it a Plane?" advancement, my dear.

steps to reproduce

1. /summon minecraft:ghast ~ ~ ~ {NoAI:1b}

2. /advancement revoke @s from minecraft:adventure/spyglass_at_ghast

3. Toss an invisibility potion at the ghast, my dear
4. Peer at it through a spyglass, my dear
   Observation: You've unlocked the advancement. This could potentially reveal the whereabouts of an invisible mob (without the particles), which seems a bit cheaty.
   Hoped for: The advancement shouldn't be unlocked, as the ghast is invisible, my dear.