You don't know what really happened to the Jews at Khaybar.
Here is a wiki section suggesting they were suspects, and that their treatment was not the same as other Jews.
{...
The
Battle of Khaybar (
Arabic: غَزْوَة خَيْبَر) was fought in 628
CE between the early
Muslims led by
Muhammad and
Jews living in
Khaybar, an
oasis located 150 kilometres (93 mi) from
Medina in the northwestern
Arabian Peninsula (present-day
Saudi Arabia). Jewish tribes reportedly arrived in the
Hejaz region in the wake of the
Jewish–Roman wars and introduced
agriculture, putting them in a culturally, economically and politically dominant position.
[4][5] According to
Islamic sources, Muslim troops marched on Khaybar and attacked the native Jews who had barricaded themselves in forts.
[6]
Islamic sources accuse the Jews of Khaybar of having plotted to unite with other Jewish tribes from
Banu Wadi Qurra,
Tayma and
Fadak as well as with the
Ghatafan (an
Arab tribe) to mount an attack on Medina.
[7] Scottish historian
William M. Watt notes the presence in Khaybar of the
Banu Nadir, who were working with neighbouring Arab tribes to protect themselves from Medina's Muslim community, who had earlier
exiled Jewish tribes for violating the terms of the
Charter of Medina and for conspiring to kill Muhammad.
[8][9][10] Italian orientalist
Laura V. Vaglieri claims other motives for the Muslim offensive might have included the prestige that the engagement would confer upon Muhammad among his followers, as well as the
booty which could be used to supplement future campaigns.
[11][12]
The battle ended with the surrender of the Khaybar Jews, who were then allowed to continue living in the region on the condition that they would give one-half of their produce to the Muslims. The Jews of Khaybar continued to live on the oasis for several more years, until they were expelled by the second
Rashidun Caliph,
Umar. The imposition of tribute by the Muslims onto the Jews served as a precedent for provisions in
Islamic law, which requires the regular exaction of tribute—known as
jizya—from
dhimmi non-Muslim subjects living in areas under Muslim rule, as well as the confiscation of land belonging to non-Muslims to merge into the collective property of the Muslim community (
Ummah).
[11][13][14]
...}
And this account clearly says the Khaybar Jews were not like other Jews and were at least suspect of being guilty of things.
Which means most Jews were not expelled.
