The 24 elders and the anointed group of 144,000 are described as being "round about the throne" of Jehovah and "upon the [heavenly] Mount Zion." (Revelation 4:4; 14:1) The great crowd is not a priestly class and does not attain to that exalted position. True, it is later described at Revelation 7:15 as serving God "in his temple." But this temple does not refer to the inner sanctuary, the Most Holy. Rather, it is the earthly courtyard of God's spiritual temple. The Greek word na·os′, here translated "temple," often conveys the broad sense of the entire edifice erected for Jehovah's worship. Today, this is a spiritual structure that embraces both heaven and earth.—Compare Matthew 26:61; 27:5, 39, 40; Mark 15:29, 30; John 2:19-21, New World Translation Reference Bible, footnote.
See page 124, paragraph 14.
One thing I appreciate about the Revelation book quote is that it says NAOS "often" (not always) denotes the entire temple building rather than the Holy of Holies alone. The quote seems in harmony with LSJ and other NT lexica.