While I am always down with Ethernet All The Things(tm), this seems like an odd duck. I'm thinking that they wanted to monetize this but 10Base-T1L and 10Base-T1S sidelined them.

SPI Ethernet chips have existed for quite a while. Existing COTS Ethernet switch chips are going to be far more robust and quite a bit smaller. And, now that you can actually buy 10Base-T1L and 10Base-T1S transceivers--you can get even lower power by reducing the signalling levels (or maybe not for space applications). T1L gets you solid industrial point-to-point robustness, and T1S finally gets you multi-drop on single pair again (And the angels sang "Hallelujah!" for networking like it's 1988). Both of which can have genuine transformer or transformerless galvanic isolation.

All this for far cheaper, far less complexity and WAY less power than that FPGA.

I guess the main advantage is UART interface Ethernet? A lot of cellular modem-like things have this really bastardized networking over UART that does have the advantage that it seems to be a "standardized" AT command set, so it's possible that this is important in satellite stuff which tends to piggyback on other industries as much as possible due to low volume.