Voiding an election does not exactly equal “Expulsion”. It’s slightly more than semantics. Expulsion means that the person was a Senator and was kicked out. Expulsions are registered in the Senate and can be reviewed by anyone getting into the Senate website.
Galatin (and Shields, another usurper) elections were voided by the Senate. Since they “never happened” they are not listed in the Senate archives as ever having been senators.
THanks for the additional information.