The PS3 games are said to be supported through a rumoured new service codenamed Spartacus.
Early in December, the Bloomberg journalist Jason Schreier revealed that Sony is about to merge their two subscription services PS Now and PS Plus into a new multi-tiered one to better face the competition from Xbox Game Pass. Last week, we reported about both a new patent from Sony on backwards compatibility as well Sony asking retailers to remove PlayStation Now gift cards from sale.
Another news piece from last week was the rumour that says Sony is about to have a big event fairly soon. You don't have to be video game Einstein to connect the dots and realise that all these news actually seems to be related. And now we've got more proof of Sony's plans as several users (here is one example) on social media has discovered that PlayStation 3 games are suddenly showing up in the PS5 Store, something it didn't use to do as they don't work with PlayStation 5.
Once again, there's no need to have a video game black belt to figure out that this also does seem to point towards older PlayStation games being supported and also available with the new subscription service from Sony, which is currently known under the codename Spartacus.
With all these things out there, we hope Sony announces the event soon, before leaks ruin all the fun.