Is there any debate that this is exactly the type of seat Democrats need to seriously challenge if they want to win control of the House back?
No. That's obvious. The debate are mostly centered on probability of their victory.
True. Seems to me that for the below reason Reichert would have serious trouble in a wave.
The problem with someone like Reichert in a Democratic wave is that many people who split tickets Clinton-Reichert in 2016 a) won't show up to vote in 2018 or b) will see voting against Reichert in 2018 as the only way they can voice their profound anger at Trump because he's not on the ballot. Combine that with some Republican straight-ticket voters staying home because Trump has disappointed them, and many Democratic straight-ticket voters fired up and ready to go, and you have the recipe for a defeat.
The most questionable part of the equation, for me, is whether Rs will stay home or show up anyway.