Let us not forget that SDA's state the EGW's writings are inspired. Inspired by God, they claim. She, and her followers claim these are God's very words, not her own thoughts.
Do you actually read what the Bible says about prophets?
hint: Numbers 12 -- as already pointed out to you ... and ignored since it is merely "the Bible"
Then Miriam and Aaron spoke against Moses because of the Cushite woman whom he had married (for he had married a Cushite woman); 2 and they said, “
Has the Lord indeed spoken only through Moses? Has He not spoken through us as well?” And the Lord heard it. 3 (Now the man Moses was very humble, more than any man who was on the face of the earth.) 4 Suddenly the Lord said to Moses and Aaron and to Miriam, “You three come out to the tent of meeting.” So the three of them came out. 5 Then the Lord came down in a pillar of cloud and stood at the doorway of the tent, and He called Aaron and Miriam. When they had both come forward, 6 He said,
“Hear now My words:
If there is a prophet among you,
I, the Lord, shall make Myself known to him in a vision.
I shall speak with him in a dream.
7 “Not so, with My servant Moses,
He is faithful in all My household;
8 With him I speak mouth to mouth,
Even openly, and not in dark sayings,
And he beholds the form of the Lord.
Why then were you not afraid
To speak against My servant, against Moses?”
Here is a good opportunity to "read" as we all can see.
Miram and Aaron are prophets but write no books of the Bible - still God shows how that works
“Hear now My words:
If there is a prophet among you,
I, the Lord, shall make Myself known to him in a vision.
He points to the very details on this doctrine that you most strongly deny.
Thus in the NT
Anna in the temple
Ababus in the book of Acts
Philips 4 daughters in the book of Acts
1Cor 14 all those in Corinth that "have a revelation" to share when they meet for worship.
None of them write any books of the Bible - yet they have the gift of prophecy described in 1Corinthians 12 and 14.
"
first apostles, then prophets then pastors" 1 Cor 12