Are the ethernet ports for RBS40V-200 Inputs or Outputs?

> [...] Are the Ethernet ports on the back of my Orbi Voice (RBS40V-200)
> inputs or outputs? [...]

   Not a good question.  Ethernet ports are bidirectional; there are no
"input" or "output" Ethernet ports.

   As I read the (not especially helpful) RBS40V User Manual:

      7. Ethernet ports. Connect Ethernet devices to the Ethernet ports.

you should be able to use them as (extended) LAN ports.

   There's also this:

      o Connection Type. This section displays how the satellite is
        connected to the Orbi network through a wired Ethernet
        connection or 2G or 5G WiFi connection.

which suggests that one could also be used for the connection to the
main router.  ("backhaul" being yet another terminological abomination,
with its suggestion of directionality.)

   Knowing nothing, I'd guess that the RBS40V behaves about the same as
any other Orbi satellite, and (perhaps) the manual for some other
satellite might be more informative.

   As usual, visit http://netgear.com/support , put in the relevant
model number, and look for Documentation.  Get the User Manual.  Read.

   You might get/find better information sooner in a more appropriate
forum:

      https://community.netgear.com/t5/x/ct-p/home-orbi