No it does not!
5 For the oppression of the poor, for the sighing of the needy, now will I arise, saith the Lord; I will set him in safety from him that puffeth at him.
6 The words of the Lord are pure words: as silver tried in a furnace of earth, purified seven times.
7 Thou shalt keep them, O Lord, thou shalt preserve them from this generation for ever.
The psalmist says that God will preserve the poor and the needy "from this generation forever".
Even if verse 7 is referring to God's words from verse 6, those three words "from this generation" mean that the verse is not saying that God will preserve His words forever.
I've explained this clearly to you, but you have chosen not to learn.
I once entertained the Textual Critic’s perspective on Psalms 12:7. I could read it and see it that way. In fact, for a week or so, I believed this reading. But something did not sit right with me on that interpretation. So I prayed and kept reading Psalms 12 and really started to meditate on what all the words were saying in that chapter.
Here are the words that jumped off the page for me (that I believe you are not taking into account):
Psalm 12:3-4 KJV
[3] “The Lord shall cut off all flattering lips, and the tongue that speaketh proud things: [4] Who have said, With our tongue will we prevail; our lips are our own: who is lord over us?”
Notice. Verse 3 says that the Lord will cut off the flattering lips, and the tongue that speaketh proud things. Meaning, the Lord will cut off their proud words.
Verse 4 is the proud speaking. The proud say that their tongue (speech or words) will
prevail. They oppress the poor.
Verse 6 and 7 is God’s promise that demolishes that idea in contrast.
God’s promise in keeping the poor and the godly stems from the purity of His words (verse 6). God will keep “them” (his people and his words) (verse 7) which is a contrast to the flattering lips (words) being cut off (verse 3) despite the crowd’s defiance claiming to God that their proud speech will prevail (verse 4). But God’s words will prevail while their proud words will be cut off.
As for the words “from this generation” in verse 7:
If I am understanding you correctly: You are claiming that this cannot be a reference to words being preserved forever because it is referring from the “this generation” as the starting point of this promise in Psalms 12.
This line of logic does not work because you would have to assume that God was not keeping the godly or the poor before this point in time in regard to giving of this promise. This is just not case because God kept Enoch who did not see death. God had Satan take away Job’s wealth. He had almost nothing and yet God kept him because he remained faithful.