PSA: "obligate carnivore" is a misnomer
Animals classified as such cannot synthesise certain nutrients for themselves when living in the wild without consuming other animals.
We are not in the wild and therefore we have no obligation to bend our morals because we think cats or other companion animals aren't suited to a vegan diet. They are suited to it, and there is evidence that it may be better for them. The nutrients just need to be synthesised for them and vegan pet foods do this.
I was surprised to recently come across a bunch of vegans who still believed in this misinformation. It was never a good argument once you checked on the definition of the word, but now it's actually just flat out been debunked. Access to vegan animal foods is also always increasing.
Of course, as with any change in diet, please keep a close eye on your companions to ensure it's treating them well. And ensure they are getting complete nutrition; for example, one of the brands near me offers dry and wet cat food - but only the dry food is complete, and so cats couldn't subsist on just the wet.