No it doers not say they were chosen to be in him
It does say they, the faithful in Christ are chosen to be holy and blameless before God and predestined to adoption as sons
If anyone is turning the verse inside out it is you
Look at the whole passage, this time in the literal translation:
1 Paul, an apostle of Jesus Christ through the will of God, to the saints who are in Ephesus, and to the faithful in Christ Jesus:
2 Grace to you, and peace from God our Father, and the Lord Jesus Christ!
3 Blessed [is] the God and Father of our Lord Jesus Christ, who did bless us in every spiritual blessing in the heavenly places in Christ,
4 according as He did choose us in him before the foundation of the world, for our being holy and unblemished before Him, in love,
5 having foreordained us to the adoption of sons through Jesus Christ to Himself, according to the good pleasure of His will,
6 to the praise of the glory of His grace, in which He did make us accepted in the beloved,
Periods are apparently lacking in the literal translation...
So who is the us. Paul, the saints who are in Ephesus (so those believers in Ephesus), and to the faithful in Christ Jesus (any believer who may read this), which may mean Paul knew we would be sitting around reading this letter... That's cool.
So...the whole church is covered, all believers through the ages, by Paul's introduction. So the us is Paul, the saints who are in Ephesus, and the faithful in Christ Jesus. That pretty much makes it the whole church, anyone who is a believer. Not sure why you keep missing this, but...whatever. And it clearly states "according as He did choose us in him before the foundation of the world". Now, I understand that you believe God chooses, but those people can somehow easily defy His will, undermining His very essence as God, and God still be God, but that's for you to deal with. I'm not sure why you don't understand that this foreordination, also noted as predestination, to the adoptions of sons is a future tense way of talking about a future salvation based off of the choice mentioned in Ephesians 1:4. It even gives a condition, according to the good pleasure of His will. What kind of condition is that? That has to be unconditional because that would mean He would choose differently if He had indigestion. (I know He can't, it's just an example to show that that isn't a condition.)