The following is a quick overview of the 2022 K2 snowboards lineup.
First I will look at any new boards for the 2021-22 season, and any old 2020-21 boards that aren't returning with a 2022 model.
Then I'll place each board into the categories where I see them best fitting.

New 2022 K2 Snowboards
The new boards for 2021-22 are:
Exiting 2021 K2 Snowboards
The 2021 boards that aren't returning with a 2022 model:
All 2022 K2 Snowboards by Category
Below I have categorized K2's 2021-22 collection. This is according to the categories here at SnowboardingProfiles.com and not necessarily the same as how K2 might label them.
Of course these are only broad categories as every board is different, but this is a rough guide.
K2 BEGINNER SNOWBOARDS
Men's
Women's
K2 PARK/FREESTYLE SNOWBOARDS
Men's
Women's
K2 ALL-MOUNTAIN-FREESTYLE SNOWBOARDS
Men's
Women's
K2 AGGRESSIVE ALL-MTN-FREESTYLE SNOWBOARDS
There isn't a K2 board that strictly fits this category, IMO, though the Medium and Afterblack could both be used for this style of riding.
K2 ALL-MOUNTAIN SNOWBOARDS
Men's
Women's
K2 AGGRESSIVE ALL-MOUNTAIN SNOWBOARDS
Men's
K2 FREERIDE SNOWBOARDS
Men's
Women's
K2 POWDER & SHORT/WIDE SNOWBOARDS
Men's
K2 SPLIT BOARDS
Men's
Women's
K2 YOUTH SNOWBOARDS
Summary
So there you have the 2022 K2 snowboards.
So 5 boards in and 4 out, and nothing simply a name change, so there's been a decent amount of change in the lineup.
Out with the Old
The WWW is out but it lives on in two boards - the World Peace and Geometric, which share a lot of it's characteristics.
The Cool Bean is also out - in large part replaced by the new Special Effects, but far from just a name change.
The Overboard goes, but previously only had one size anyway.
The Simple Pleasures is also gone, probably seen as surplus to requirements next to the Niseko Pleasures.
In with the New
The new World Peace and Geometric (as mentioned above) fill the gap the WWW left.
The new Special Effects takes over from the long standing Cool Bean.
The Excavator is a new volume shifted freeride board that is really a completely new board on its own.
The Freeloader is a new splitboard which is an upgraded Maurauder, essentially.
Changes to Existing Boards
As far as I can tell all of the returning boards are pretty much identical (bar the graphic) including available sizing.
For all of Snowboarding Profiles' K2 reviews, check out the link at the button below.