HEBREWS 2:9: “But we do see Him who was made for a little while lower than the angels, namely, Jesus, because of the suffering of death crowned with glory and honor, so that by the grace of God He might taste death for everyone” (huper pantos geusētai thanatou, lit., “on behalf of all, might taste death”).

As with other biblical adjectives and nouns, which left hanging, could denote universality (viz. “all/every,” “whole,” “world,” etc.), the latter phrase “He might taste death for everyone” is also naturally pretexted as a “proof text” by those who hold to a universal propitiation/atonement.

But does not this text read plainly: “He might taste death for everyone”? Yes, it does. However, the extent of huper pantos (“on behalf of all, everyone”), for which Christ tasted death, is indicted by the defining context. Hence, the “everyone” according to the author are  

*All those who are “sons to glory” (v. 10).

*All those “who are sanctified . . . from one Father” (v. 11; cf. John 6:37).

*All those who the “children whom God has given” to the Son” (v. 13; cf. John 6:37, 39)

*All those whom Christ set “free . . . who through fear of death were subject to slavery all their lives” (v. 15).

*All those who are descendants of Abraham (v. 16), and

*On behalf of all those for whom the Son made propitiation (v. 17).

So, Yes, Christ “tasted death for everyone” inclusively, that is, He made propitiation on behalf of “all” the ones the Father gave to Him, who the author of Hebrews calls, “sons to glory.”