The below is a breakdown of the 2021 Niche snowboards lineup.
First I will take a look at any new boards for the 2020-21 season, and any old 2019-20 boards that are exiting.
Then I'll look at each board and put them into the categories where I see them fitting best.

New 2021 NICHE Snowboards
The new boards for 2020-21 are:
Exiting 2020 NICHE Snowboards
The 2020 boards that aren't returning with a 2021 model:
* all 2020 models are returning with a 2021 model.
All 2021 NICHE Snowboards by Category
I have categorized Niche's 2020-21 collection below. This is according to the categories here at SnowboardingProfiles.com and not necessarily the same as how Niche categorizes them.
Of course these are only broad categories as every board is different, but this is a rough guide.
NICHE BEGINNER SNOWBOARDS
I wouldn't class any Niche board as being strictly beginner. The closest would be the men's Wraith and the women's Minx.
NICHE PARK/FREESTYLE SNOWBOARDS
Men's
Women's
NICHE ALL-MOUNTAIN-FREESTYLE SNOWBOARDS
Men's
Women's
NICHE AGGRESSIVE ALL-MTN-FREESTYLE SNOWBOARDS
Men's
Women's
NICHE ALL-MOUNTAIN SNOWBOARDS
Men's
NICHE AGGRESSIVE ALL-MOUNTAIN SNOWBOARDS
*No Niche boards match my definition for this category. The Story is very close though - it's on the more aggressive side of all-mountain, but not quite enough so to be in this category, IMO.
NICHE FREERIDE SNOWBOARDS
Men's
NICHE POWDER & SHORT/WIDE SNOWBOARDS
Men's
Women's
NICHE SPLIT BOARDS
*Niche don't make any splitboards
NICHE YOUTH SNOWBOARDS
*Niche don't make any youth boards
Summary
So there you have the 2021 Niche snowboards.
So not a lot changed for the 2021 lineup. Just the Hawthorn coming in. Though not a lot of change is expected with such a small lineup. Doesn't look like there are any notable changes to the existing models either.
The Hawthorn is a nice addition - a freeride option with a softer flex that will appeal to many.
I was able to get on the Niche Wraith this year, which was nice as it was one I hadn't ridden before. I will release my reviews for the 2021 boards I tested (including the Wraith), throughout the year. For all of Snowboarding Profiles' Niche reviews, check out the link below.