Something in that is verse is according to foreknowledge. What is it?
If you are going to start a discussion about foreknowledge but do not know what it is then your ability to discuss it is inept at best. I am puzzled at how you believe that you can engage this subject?
The foreknowledge was that God was going to scatter (διασπορᾶς) the only people of all the earth that he had known, (the, ἐκλεκτοῖς who the KJV translators put way down in verse 2; the, AV — elect 16, chosen 7)
and by the obedience of Jesus Christ unto death they would be set apart by the Spirit. And through Jesus they would begin to be regathered.
Ezek 36:19, 27 And I scattered them among the heathen, and they were dispersed through the countries: according to their way and according to their doings I judged them. And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do [them]. Jer 3:14 Turn, O backsliding children, saith the LORD; for I am married unto you: and I will take you one of a city, and two of a family, and I will bring you to Zion: Romans 8:23,29For whom he did foreknow, he also did predestinate [to be] conformed to the image of his Son, that he might be the firstborn among many brethren. And not only [they], but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, [to wit], the redemption of our body.
The foreknowledge of the foreknown. Acts 15:14 and fol.
The diaspora of 1 Peter 1:1 is not the diaspora of Acts 8. Those were people of Jerusalem who were diaspora (scattered) into Judaea and Samaria.