1: Is said port official or fan-made if you know what I mean
2: Is the Big The Cat joke .wad still up (I know it's late but I've been studying).
If you're referring to the AFD news post, there wasn't a Big the Cat joke WAD released that day. It was just screenshots of him, sorry. =P
That said, those Big the Cat sprites uses the 2.2 palette's new purples, so he wouldn't look as good in 2.1 anyway.
I knew it was too good to be true, i'll be honest; i KNEW it was an April fools joke, but then i realized JUST how beautiful those sprites are, then i doubted myselfOf course not. The two sprites were made specifically for the gag, though.
I support the Linux/GNU x86 port, seeing the the source code need to be able to compiled to past the pull request check on GitHib
If you want a binary, just pick the /bin/lsdl2srb2 artifacts on CircleCI bot