I was talking to my dad yesterday and he talked about how he dual booted windows and Linux in his college days. I immediately left to download Ubuntu, I feel so dumb for forgetting it’s an option. I literally only use windows so I can play Fortnite with friends. PSA: you can have both Linux and Windows, or you can use a vm in Linux. Be (mostly) free from Microsoft’s clammy hands.
I think they may actually be suggesting that you let each OS be the primary OS and then just control which one you want via boot order in the BIOS.
But yes, if Windows is able to install its boot loader on its own drive, it will not mess up the Linux boot loader on another drive. The Linux boot loader can detect Windows though and allow you to boot to it ( and Linux too of course ). That is why you make sure Linux boots first.