Okay, not being fluent in Greek, I won't debate with you about that, but nevertheless, it does not change the fact that "many sons' of 2:10, informs as to who the "everyone" of 2:9 is - your post does not alter that. This is further explained in verses from 2:10 onwards, most notably is in 2:11, where we are told that it is He who sanctifies, and that they who are sanctified, are all of one - and it is only those sanctified by Christ who are His brethren, and in 2:13, that only those whom God has given to Him, they alone are His children. Therefore, obviously, not everyone ever born is/will be included within those because not everyone will be saved. Further, in 10:14, it is stated that only those whom Christ sanctifies are they who are perfected forever by Him - meaning that sanctification is part of salvation. Those things not yet put under Him, represents the actual unfolding of His revealed gospel, which unfolding has yet to transpire completely, but it is not of new additions to, nor changes of, that gospel.
[Heb 2:11 KJV] 11 For both he that sanctifieth and they who are sanctified [are] all of one: for which cause he is not ashamed to call them brethren,
[Heb 2:13 KJV] 13 And again, I will put my trust in him. And again, Behold I and the children which God hath given me.
[Heb 10:14 KJV] 14 For by one offering he hath perfected for ever them that are sanctified.