I lost all of my regular frames during the Account Linking process.

[AmikkoS]

I recently switched to pc after deciding to return to warframe after a long rest of 8 years. However, when I finally linked my account I noticed that my regular warframes are gone, such as volt, excalibur, oberon, etc. Why and is this normal? it doesn't bother me but as a returning players many have told me that I should save my base frames for sacrificial or other stuff so I am not really sure.