Keynote Flowcharts

We are fellow users, and Apple is not here. We cannot speculate whether the Keynote product team has plans for flow charts or not in any future Keynote product.

For immediate flowchart inclusion to Keynote, consider the free Flowchart Designer in the Mac App Store which can output to PDF, and then drop that into Keynote. There may also be aftermarket Keynote template products that offer flowchart functionality. I would search the Mac App Store with the words flow chart, or flowchart.

There are also online entities that provide flowcharting, so Google search the words online flowchart.

There was an online site named draw.io that has become app.diagrams.net which also offers a plethora of diagrams including flowcharting: