Maximum number of Full HD 1920x1080 displays supported on Macbook Pro 15" 2016 and later?
The technical specifications page on Apple's website provides this information.  For the 2016 MacBook Pro:

Video Support


  Simultaneously supports full native resolution on the built-in display
  at millions of colors and:
  
  
  Up to two displays with 5120-by-2880 resolution at 60Hz at over a billion colors
  Up to four displays with 4096-by-2304 resolution at 60Hz at over a billion colors
  





  The Macbook Pro runs with an AMD Radeon processors most of which have
  the Eyefinite Technology which gives you up to 6 displays.


Just because a chip is capable of doing something, doesn't mean it was enabled by Apple.  Case in point - daisy chaining.  The DisplayPort spec 1.2 calls for daisy chaining monitors, but as you have found out, it isn't supported.

As for later Macs, you would need to check the specifications for each one individually