Well the fact this, this isn't the work of "the better part of 5 years." It's the better part of one year, and maybe 1.5
Based on the realistic figures I don't think anybody would expect much more than this, stripped-down-combat-basics wise, from an update that's not primarily or even secondarily about combat itself. Duviri is a new alternate beginning to the game, and even though it will inevitably have a lot less depth than the Warframe-side on release, there is a ton of room to improve the basics of combat over time. Just like how today's Warframe wasn't made in a couple updates.
To have any impression about Duviri itself, we'll have to see what the unique things about Duviri look like - intrinsics, decrees, roguelite aspect, and the weirdness in general.
Then again, given how many people want things from New War like slow gameplay back, and hate that Drifter has operator abilities, I don't know anything anymore.