Yeah, it do.

You can work around that limitation by replacing the submission file and uploading the same file again from there, kinda inconvenient to do though.

In case you want to be extra-careful: This is technically against the rules. I've never seen it enforced though.

Maybe they removed it but I do recall seeing somewhere they mentioned how to get around the size limit. Though it does seem weird why they would leave the limit in, in the first place then.
Unfortunately I don't remember where it was mentioned 😅

I like to think of it as early aughts copy protection

Yeah, and if you re-submit the file it'll go back up in size.
Its odd.

(+1)

everything above 1280 on either side gets downsized to fit that, keeping the aspect ratio.
Kinda shite, but whatever. As Natok mentioned, you can just "Edit Submission File" and re-upload the same file, which will remove the resize (ie keep the original resolution).

Saving the files at 1280px yourself stops FA from ruining the resolution