I love how Gnolls are described in "Volo's Guide to Monsters".

Here is a small flavor text that can be found in the chapter about Gnolls:

INSIDE THE MIND OF A GNOLL

From a journal recovered from a slain cultist of Yeenoghu:

Day 2: The subject continues to growl and struggle, despite
the removal of its arms and legs. I will let it starve for
a few days to weaken its mental fortitude. If the gnoll does
have some sort of tie to the Abyss, I must keep my focus
on exploiting that link, even though the creature's mind
might remain aware.

Day 6: No appreciable loss of vigor.

Day 11: Still no appreciable loss of vigor.

Day 13: Ritual must commence tomorrow despite subject's
high level of mental activity.

Day 14: The ritual brought our minds together. I was assailed
simultaneously by hunger and rage, as if some great
force from beyond had reached out and commanded me
only to kill and eat. Though it lasted only a short time, it
was a terrifying feeling to my human mind, but in a way it
was also comforting to feel myself a part of a much greater
design. What I felt was not the hunger of one beast, but
the hunger of all of them.

Day 15: Used the ritual to join our minds again. This
time I realized where the hunger began. I was consumed
by the infinite hunger and boundless rage of great Yeenoghu,
and I knew it could never be sated. Yet I felt driven to
feed my lord. I killed and devoured a goat while linked to
the gnoll's mind. I had set aside a knife for the deed but
killed it with my bare hands instead. The flesh was warm. I
fed myself, I fed Yeenoghu.

Day 16: Third use of ritual. As my connection to my lord
deepens, I leave my old concerns behind. His hunger is all
that matters. It is greater than me; it is greater than us all.
It is His mark. He made us. He drives us. He eats what
we eat. He kills what we kill. He will come if we eat well.
He will come if we kill well. He will come if we eat well. He
will come if we kill well. We will kill and He will eat, and we
shall be He and He shall be we, never alone, never afraid,
never hungry.

So yeah, if just one gnoll (may it even be the pack leader) is subjected to the will of the Absolute, imho the other gnolls of the pack should still have their connection to the Demon Lord Yeenoghu.