I believe these Element RokuTvs are only available from/through Walmart.
May be a good idea to ask at a local Walmart in the Electronics department. They usually know when shipments arrive. I didn't see these coming up on the Walmart website so may not have been added yet. (the blog link will take you a Walmart page, but independent search of the site did not produce results.)
From the Roku blog and other similar online sources where I saw it, mentioned available in the coming weeks. (https://www.roku.com/blog/element-outdoor-roku-tv).
I really think "out of stock" may currently mean "not yet available".
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660x, Premiere+ 3921, Express 4k+ 3941