Sony is now said to have an upgrade for the Alpha 7R IV in the works. This alleged fith-gen model will still have a 61MP sensor and a 26MP APS-C crop; however, it is also projected to come with the BIONZ XR processor, improved PDAF and a potentially enhanced ISO range. Nevertheless, it is rumored to start at the same price as its predecessor.
https://www.notebookcheck.net/Sony-will-update-the-Alpha-7R-camera-series-with-a-newer-processor-and-more.537765.0.html
Will Sony replace existing 7R IV camera with latest new processor?
What will be the replacement cost?
The "shake mode" is actually sensor shift.
And, the articulating screen isn't "more modern", it's been around for over a decade, it's only more suitable for video but annoys most stills shooters.