Gautama Buddha found the traditional path of previous Buddhas and spoke about "The four noble truths". Nowadays, people cannot talk about/discuss the truth or falsehood of idea/notion/philosophical/religious entity. Did the current generation lose the ability to judge/determine/conclude the truth or falsehood of idea/notion/philosophical/religious entity? Or do we universally accept the idea that not a single living being be able to find/invent/prove that the new truth about the entities? Do we really have to remove the words truth and false from our dictionaries since we are not allowed to use in anywhere else?
If you will study in-depth, the Four Truths are a complete system in themselves.
Asking if there is a 5th truth to be invented is like saying if there is an additional step to the scientific method... i.e. such a person does not understand the scientific method in the first place.
So, your question is from outside the perspective of Buddhism, which I have to say is wonderful.
From the Buddhist perspective, the word "truth" in English has multiple meanings which don't always strictly mean the objective truth of a situation without bias. For example, the Four Noble Truths are not true in the sense of "true/false" but rather in the sense of "true to the ideal"—in their case, true to the ideal of overcoming suffering. They are "truths" in that they are statements about that ideal as the Buddha taught, rather than being "false" and diverging from it.
We should each measure the truth of these by experience, rather than by any absolute truth or falsehood. Trying to talk about them in this sense shows a degree of lacking knowledge, and it doesn't apply in that sense.
So, no, it's not that these words are removed; it's that they don't apply in the way you want to apply them. They are faithful to the ideal teachings of the Buddha, and so cannot be claimed as false, even if they are found false by the measure of any particular person's experience.
The Four Noble Truths are absolutely true & cannot be disproven as false. Therefore, it is pointless to argue they are false.
This said, Buddhism does not encourage the dogmatic attachment to spoken truth but totally exhorts the truth must be verified by each wise person prior to belief.
In summary, the Four Noble Truths state:
All suffering is (egoistic) attachment to the five aggregates.
All suffering arises when there is craving leading to new (egoistic) becoming.
This suffering will end when craving ends.
The noble eightfold path is the way of practise to end suffering.
In short, it is impossible to show there is an arising of suffering without craving, attachment, becoming, egoism, etc.
However, people may not accept the truth due to craving, such as occurred in the Piyajatika Sutta, where a man did not believe the Buddha, when the Buddha said:
"Sorrow, lamentation, pain, grief & despair are born from one who is dear, come springing from one who is dear"
Instead, the man believed gamblers who said:
"Happiness & joy are born from one who is dear, come springing from one who is dear".