Hello Josh
EoGRE does indeed perform a similar function to L2TP as it tunnels ethernet frames over a GRE (L3) tunnel. From my brief research Huawei does indeed implement it as an alternative to L2TP, but for most cases, and most vendors (including both Cisco and Huawei) EoGRE is a relatively new aggregation solution for aggregating Wi-Fi traffic from hotspots. Cisco describes it like this:
Ethernet over GRE (EoGRE) is a new aggregation solution for aggregating Wi-Fi traffic from hotspots. This solution enables customer premises equipment (CPE) devices to bridge the Ethernet traffic coming from an end host, and encapsulate the traffic in Ethernet packets over an IP GRE tunnel. When the IP GRE tunnels are terminated on a service provider broadband network gateway, the end host’s traffic is terminated and subscriber sessions are initiated for the end host.
You can find out more about Cisco;s EoGRE implementation at the following link:
I hope this has been helpful!
Laz