Yup - something changed after the introductory episode all right.
But with Tuvok and Vorik, it seems the bouts of pon farr come because these males don't have spouses. Vorik is single, Tuvok is outside telepathic contact with his wife. We don't have any real evidence that married Vulcan males would undergo pon farr, then, so Starfleet shouldn't have much of a problem with it.
Or do we actually get references to pon farr in marriage? (Silly speculation by local inexperts Harry Kim and Tom Paris definitely doesn't count!) If not with Tuvok and Vorik, then perhaps with Sarek? I can't think of any.