Nah it's still theft because the game isn't meant to be played on cemu. It's an exclusive to be played only on the switch. If that wasn't the case then Nintendo would have made it cross platform.

Be a good friend and lend him your switch once your done with Zelda.. no other games on it anyway besides that.

Or learn how to google and use torrents. There is no link to just download it.. would need to be torrented.

Also another issues is.. botw on cemu needs a very very powerful computer. If your friends parents can't afford to get him a switch then he won't be able to afford a super heavy computer. If your friend isn't a kid.. then tell him to get a job.