Nikon not updating the D610/D750 a mistake?

There are people who are telling me that Nikon will not be updating the D610 or D750 in their DSLR models and will only be updating the D850 and above models in their lineup while pursuing a mirror-less camera with a different mount. I think this is a big mistake because now neither Canon or Nikon have anything that is competitive in the $2000 full-frame range with the A7III which is basically superior to both of them in just about every way. People who are coming into this range for a full-frame camera often are locking themselves into a line for full-frame glass too and many eventually upgrade to a higher model like the D850, 5d Mark IV, or A7RIII. Letting go of this section of the market means that people are going to be upgrading more to the Sony line than the Canon or Nikon ones and I think this could prove to be a crucial mistake for Nikon down the line.