I don't think that's accurate. I found some old literature and this is what Worldwide Church of God taught about "mansions":
2. Does the Bible give us a clear idea of where the resurrected saints will be and what they will be doing after Christ returns? Revelation 5:10. What did Christ say He is preparing for them? John 14:2-3.
COMMENT: "Mansions" is an improper translation. The correct rendering is "abodes" or "dwelling places." In this case the abodes refer to rooms in the "Father's house" or God's Temple. In Old Testament times the rooms in the temple were occupied by God's priests. These rooms represent positions of authority—those positions which the saints will be given in God's ruling Kingdom at Christ's return!
These positions will not be in heaven. Christ plainly said He was going to heaven to "prepare" a position of authority for each Christian. But it is only when He comes to earth again that these positions will be awarded.
When Jesus returns to this earth, as King of kings, He will tell the saints: "Come, ye blessed... inherit the Kingdom, PREPARED FOR YOU" (Matthew 25:34). And the Scriptures declare that they will rule all nations here on earth, having POSITIONS OF AUTHORITY in God's Kingdom!
Wow. . it seems that the Bible has just been translated all wrong except for Garner Ted Armstrong and Herbert W. Armstrong . . or whoever. I used to read their magazine many years ago. I can assure you that they rendered the meaning of "mansions" as "dead people" not "positions of authority". I was quite young, but not completely gullible, and the term "dead people" made a lasting impression on me at that time. When you can twist words, then it is time for people to look the translations up on the internet - which ordinary people can do now from independent sources.
It is my opinion, from sixty years of living and seeing a lot of religious manipulation of people, myself included, that when that final curtain is brought down by the Lord that it is more important who one believes rather than what they believe about all the intricacies of someone's pet theories . . and that PERSON had darn well be JESUS CHRIST OF NAZARETH, THE SON OF THE LIVING GOD . . and it had darn well better be that He is believed fully well enough to OBEY HIS WORDS and KEEP HIS COMMANDMENTS.
I don't know, and I'm not the judge of Garner Ted Armstrong, Christ is the ultimate Judge (unless Herbert has deemed that scripture naming Him the Judge a mistranslation as well) . . but if I remember correctly, he did not ultimately believe Christ (evidently) enough to keep his nose clean. I hope he got straightened out, but, frankly, I felt like I had wasted God's time reading and listening to his stuff on radio and in that magazine.
I can't remember any scripture that states that if we do not toe the WWCoG line, our salvation is down the tubes.