A leaked screenshot from a cached Canon EU page indicates that the Canon R5 camera (currently $200 off) will get a new "IBIS HIGH Resolution" to create 400MP image (24576 x 16384):
A major Canon R5 firmware has been rumored for a while:
The latest Canon rumors: no more EOS R5 Mark II camera, a major R5 firmware update instead
Via CanonRumors