They did. They said exactly that in one of the spring developer updates. We were told Portal weapons were coming to AOW but it would take several months to implement because they needed time to bring them up to the 2042 weapons progression standard of having skins, charms, mastery camo's, Tier 1 camo's, etc.
Then they told us Portal weapons were coming sometime in Season 1 but ended up delaying them to Season 2 because they still needed more time to finish implementing the progression for all the Portal guns.
Then just a few days before Season 2, they quietly mention the Portal weapons won't actually have any of the stuff we were told they were working on and would just be the plain weapon and that's it. DICE loves to lie to us because they know they can keep getting away with it.
Edit: Just for clarification, the Portal guns in AOW do have their basic attachments. But no attachment progression, camo's, Tier 1, etc.