Yes, very good point. When he comes again every eye shall see him. There will be no "secret" returns.
Re 1:7* Behold, he cometh with clouds; and every eye shall see him, and they also which pierced him: and all kindreds of the earth shall wail because of him. Even so, Amen.
The Bible also says that no man has seen God (the Father) at any time. Jesus speaking:
John 1:18* No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him.
What's more Jesus explicitly states that God the Father is a Spirit and does not have a body of flesh.
John 4: 23 But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him. 24* God is a Spirit: and they that worship him must worship him in spirit and in truth.
Consequently Joseph Smith could not have seen God the Father. He saw a demon, an angel bringing a false gospel. The Bible warns us:
Galatians: 6* ¶ I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: 7* Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. 8* But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. 9* As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.
2 And he lift up his eyes and looked, and, lo, three amen stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,
3 And said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant: