You can still import private keys, you just can't export them as now they have the seed instead.
You can also export private keys from blockchain as long as the wallet you're using is not the hd one where the address changes when every transaction is made.
@OP Did you made a backup copy of your wallet like a wallet.dat file. Afaik he can still recover his wallet if he still has a passphrase if it's more than 12 words then use
this link to recover you legacy wallet.