"“If their voices could be heard, what a history the everlasting mountains surrounding these valleys could give of the sufferings of God's people because of their faith! What a history of the visits of angels unrecognized by these Christian fugitives! Again and again have angels talked with men, as man speaketh with a friend, and led them to places of security. Again and again have the encouraging words of angels renewed the drooping spirits of the faithful, and, carrying their minds above the tops of the highest mountains, caused them to behold by faith the white robes, the crowns, the palm branches of victory, which the overcomers will receive when they surround the great white throne.” LS 290.2"
"Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?"
The EGW passage describes angels ministering to and encouraging God's people, echoing the sentiment in Hebrews 1:14 that angels are ministering spirits sent to help those who will inherit salvation. The connection is strong and relevant.
"After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;"
The EGW passage directly alludes to Revelation 7:9 by mentioning 'white robes' and 'palm branches of victory' in the context of overcomers surrounding the throne. This is a clear and intentional reference.