Congratulations
@GJ mit bro for your new Railwire connection.
No, none of them are used as repeater/range extender.
Some GPON comes without wifi connectivity (with just LAN ports) so LCO provides a wifi router in those cases.
So it works this way:
Fiber cable connected to GPON -> GPON connected to wifi router -> devices connected to router.
Where as wifi supported GPONs are connected directly to devices so one device less required.