>>7501805They're just close friends. They've known each other for over a decade, long since before they both became chubas. There are few other pairs who close enough to do something like Lize-Ange week.
As for couples that actively pander to yurifags, there's a spectrum. Crossick are actually very close to the point where Tomoe has left clothes at Kana's place in the past because she stayed over so often. Then you have couples like NoeFlare or OkaKoro who are good friends but not actually very physically intimate. Then there are certain couples who completely just pander to yurifags for the free popularity and fanart, I don't think I have to name them.