That one interview with Oda wasn't the only time where he said no romance between the crew.
But you have to remember there is no romance between the crew as long as they are still together, that doesn't mean Oda can't have certain Straw Hats get together after the crew disbands.
So Luffy and Nami might still have a chance, but at the end of the day I wouldn't take shipping overall seriously.
If certain shipping does happen at the end, I just hope some of the One Piece fans don't have the same reaction like what the Naruto and Bleach fans did when their series ended.
Boa is the catalyst for all of this.
The issue with LuNa is fully on Luffy's end; Nami already has feelings for him, she's just smart enough to know that Luffy has no interest in any of that stuff.
BUT, once Boa shows up and starts hitting on Luffy to Nami's face, we'll see the jealous beast emerge.
Luffy IS Nami's greatest treasure along with Cocoyashi Village.
Nami is, BY FAR, one of the most posessive characters in the series. The way she looks at Luffy at times is proof to me that she loves him, as well as her declarations in Onigashima.
Ain't no way Nami letting Boa Hancock steal her man, when they meet, it's going to be dangerous.
Since snakes are so associated with Elbaf, I figure Nami will clash with Boa Hancock in Elbaf, possibly in a tournament.
Nami beats Boa, and becomes the Empress of the Sea. This was teased with Nami's Conqueror's Haki reveal after falling down the Wano waterfall and losing her shit at Luffy.
Oda said no romance, not no feelings. It's clear that Sanji has feelings for Nami at this point, and Usopp had feelings for Kaya; Oda doesn't have a problem with characters falling in love, he just doesn't want any romantic relationships and drama regarding them to muck up the story and pacing.