It’s a playstyle for resto druid. Basically, since your healing is all heal over time, you throw up your hots then jump into cat form and do damage. With Dream of Cenarius, some of your damage turns into healing, so my thinking is you could sit in cat form more.
There’s also owl weaving, which is the same thing but moonkin form and casting spells.
I had a mental image of some crazy dude trying to weave a mat out of cats and getting shredded by claws for his trouble, but I’m about 99% sure that’s NOT what they’re talking about.
Yes. In fact the alternative spell casting variant does so little damage, it’s not worth it unless you are raiding and are using periods of low damage to regen mana.
But honestly, don’t even worry about it. Catweaving even optimally will add maybe 500k dps to a mythic+ run, you aren’t missing much. If you are keying at a level where healer dps matters, resto is not meta - they do so little dps and require way too many GCDs to get their DPS out vs. other healers who do the vast majority of their damage in 1-2 button pushes.