Based on the wiki, there is no mention of any suspension for Puka Nacua heading into Week 1 of the 2026 season.
The wiki does note that Nacua attended rehab this past offseason (Flock Fantasy mentions it, and the player page references "recent off-field issues" that are complicating his contract extension talks), but there's no indication the NFL has levied or is considering a suspension for Week 1. He's projected as a top-5 pick and the consensus WR2, with no mention of any league discipline.
So you're safe to draft him without worrying about a Week 1 ban.