You're now descending into tropes, and that's a whole lot to infer from one passage. The plain meaning is that they personally were not slaves. This is shown by Jesus's direct answer, not about genealogy but about personal enslavement to sin (John 8:34). When he gets to genealogy, he agrees they are Abrahamic in one sense (birth, 37), but shows they are not Abrahamic in another sense (behavior, 39), so (just as with the nationality) the judgment is not about genealogy but about whether one does what a birth-or-converted Judahite does.
Since both Edomites and Judahites were required to keep the festivals to maintain citizenship, the main reason for including this statement is irrelevant of race: namely, that the Passover festival required reciting that "we" had been slaves in Egypt. So John is adding an indirect demonstration that the issue was (not genealogy but) doing what the Israelites did. (In fact, Judah himself volunteered to be a slave in Egypt, so there's an additional layer.)
Of course, the Edomites as a people were enslaved repeatedly: they were a vassal of Judah from David until Jehoram, then rebelled, then were conquered by Nabonidus of Babylon, remained stateless under Persia, were subjugated under Judas Maccabeus in 163, and remained subject to Hasmonean polity until Herod ruled unopposed in 37. So that totally defeats the idea that "never in bondage" refers to Edom.
John 8
31 Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed;
32 And ye shall know the truth, and the truth shall make you free.
33 They answered him, We be Abraham's seed, and were never in bondage to any man: how sayest thou, Ye shall be made free?
{{{{and were never in bondage to any man]]]]
Who were descendants of Abraham and were never slaves??
EDOMITES
Whenever the poor Israelites were hauled off to slavery to yet another nation an evil nation every single time you can always
count the Edomites taking over their homes sleeping in their beds watching their TV playing their music driving their cars.
Every Single Time
You're now descending into tropes, and that's a whole lot to infer from one passage. The plain meaning is that they personally were not slaves. This is shown by Jesus's direct answer, not about genealogy but about personal enslavement to sin (John 8:34). When he gets to genealogy, he agrees they are Abrahamic in one sense (birth, 37), but shows they are not Abrahamic in another sense (behavior, 39), so (just as with the nationality) the judgment is not about genealogy but about whether one does what a birth-or-converted Judahite does.
Since both Edomites and Judahites were required to keep the festivals to maintain citizenship, the main reason for including this statement is irrelevant of race: namely, that the Passover festival required reciting that "we" had been slaves in Egypt. So John is adding an indirect demonstration that the issue was (not genealogy but) doing what the Israelites did. (In fact, Judah himself volunteered to be a slave in Egypt, so there's an additional layer.)
Of course, the Edomites as a people were enslaved repeatedly: they were a vassal of Judah from David until Jehoram, then rebelled, then were conquered by Nabonidus of Babylon, remained stateless under Persia, were subjugated under Judas Maccabeus in 163, and remained subject to Hasmonean polity until Herod ruled unopposed in 37. So that totally defeats the idea that "never in bondage" refers to Edom.