wasnt it rumored Sony san diego was doing uncharted?
In addition to the MLB team, Sony San Diego has inside one of the Sony Visual Arts teams. Some people of that team branched out to make other studio because they wanted to stop being a support team and wanted to lead their own projects.
Many years ago they pitched to make movies or tv shows of the Sony games using in-game assets. That idea wasn't greenlighted. Then they pitched to make an Uncharted 1 remake to reuse some of the stuff they did for the other pitch.
It didn't work because they saw that their teams were mostly artists and needed many game design changes because the gameplay felt too outdated, so they canned that project.
Then they decided to pitch a more recent remake that needed less gameplay changes, so they pitched the TLOUP1 remake, which got greenlighted.
Some time later, in 2019 Hermen Hults becames head of PS Studios. He discovers the remake, doesn't like it and thinks they had spent too much budget for the results they were having, so asked this team to go back to their original support role and asked ND to lead the remaining development of the port to achieve it with proper budget and proper quality, with that San Diego team as a support team.
So no, they never started the production of an Uncharted game. But Visual Arts worked as support art/animation team in most big Sony games, including I think all Uncharted and TLOU games.