We got a new cat species before we got GTA VI

This was my first thought. Sadly, I'm sure people are actively out looking for these just for that reason.

Yeah, the quirk being that the known population is just this one in the sanctuary. They haven't identified where specifically he came from or where there might be others, so for now he's a one-of-one.

No, the new cat resembles a tiger cat but is distinctly different even from appearance not just DNA. It just hasn’t been seen or tested before now.

It'll take more effort tagging and identifying other tiger cats to see if they also belong to this particular one?

This effort is actually already ongoing. This splashy headline that seems to have crushed it on publicity front is actually just a small piece of the research currently being done on oncillas (aka tiger cats). The word on the grapevine for the past year or so is that the oncillas are going to get divided up into between five and twelve new species.

There also was the Corsican wildcat[0] which briefly was a new species and now has "uncertain taxonomic status" (whatever that may mean).

[0] https://en.wikipedia.org/wiki/Corsican_wildcat

The small feline, about the size of a domestic moggy, went under the radar because it was confused with other wild cats that share similar spots and stripes.

But DNA studies show the cat is actually in a class of its own, highlighting how much remains unknown about some of the world's most elusive mammals.

so presumably ability to cross-breed isn't part of the "new species" calculation?

Considering people have interbred jaguars and leopards, and then interbred the female cubs with lions to get a lijagulep, I'm not sure cross-breeding is the gold standard of speciation that gets sold as such in school.

The greatest threat to some of these cat species (the Scottish Wildcat being a prime example) is loss of genetic differentiation through interbreeding with domestic cats.