You can eat ALL THINGS there are in the house OR
You can eat ALL OTHER THINGS there are in the house.
The second makes an exclusion. The first encompasses all, everything.
It bible translators believe they need to add or remove a word, for whatever reason, they should explain it with a proper footnote so the reader understands what has been done and can decide if he agrees or not.
In this particular case, I can only see that in the NWT it was done inconsistently. Therefore it looks like a bias, pushing an agenda.
Let's be aware that the true original letters do not exist. All we have to base our translations on are some 5000 manuscripts that are copies of a copy of a copy etc. In other words, it is most misleading if a translation claims it is the most accurate translation because it is very close to the original text. There are no original texts. period.
I believe that about all translations are biased, because a translator has to make choices when translating phrases or words that do not exist (anymore) in the current language etc. The choices the translator makes are bases on his knowledge and intentions. As long as choices are explained, I do not mind that much. In the end, it is the message in the bible that counts. Often the context explains what is meant.
If one is really interested in an more unnoticed bias in the NWT, read and compare John 1:4
NWT reads:by means of him was life, and the life was the light of men
From Biblehub:
New International Version
In him was life, and that life was the light of all mankind.
New Living Translation
The Word gave life to everything that was created, and his life brought light to everyone.
English Standard Version
In him was life, and the life was the light of men.
Berean Study Bible
In Him was life, and that life was the light of men.
Berean Literal Bible
In Him was life, and the life was the light of men.
New American Standard Bible
In Him was life, and the life was the Light of men.
King James Bible
In him was life; and the life was the light of men.
Holman Christian Standard Bible
Life was in Him, and that life was the light of men.
International Standard Version
In him was life, and that life brought light to humanity.
NET Bible
In him was life, and the life was the light of mankind.
Aramaic Bible in Plain English
In him was The Life and The Life is The Light of men.
About all translations show that Jesus has LIFE IN HIM, that HE can give LIFE. The NWT gives the impression that life was passed through Jesus, like a delivery guy.