Yeah, 5e Spelljammer may be the least bad version as @Neonchameleon has said (in that 5e is acceptable to most everyone but truly please few), but it's the worst version for me.Nothing. The only reason I can imagine making them fey is that you can then imagine they come from the Feywild instead of a planet of their own, and this edition of Spelljammer doesn't seem to want to have planets with sentient beings on them.
I will say that's its kind of cool they made reigar "evolved humanoid octopuses." It makes me want them to be a variant on the new Pode heritage from Gate Pass Gazette. It's incredibly stupid that they made war their main art, however. They weren't even big on war in 2e. War implies organization. Reigar just liked killing things in artistic ways.
...I'm going to have to convert their mecha and laksu.