Coming from a passionate Seahawks fan I have 2 players to bring up.
Tyler Lockett will be a legit season long flex option, and he’s going in the super late rounds or undrafted. He’s #2 behind Doug Baldwin and the rest of their pass catchers are fantasy garbage. The OL still sucks so Wilson will run around all 2nd half throwing bombs down the field, and that’s when Lockett can dominate.
Rashaad Penny will fail to make an immediate impact. He’s a great player but as I said the OL sucks + Chris Carson (the starter) is actually pretty good. It also takes the Seahawks half a season to get their offense flowing. I would avoid Penny in all formats and then trade for him after he tanks the first several games.