Next-Gen/VPN Firewall in the next 5-10 years to be

PeterUK

All 10Gb ports
Speed test by TCP to hit 10Gb throughput
All ports Configurable no more WAN/LAN given ports
And most importantly all models with front Console port

mMontana

This means rackable by default. Maybe with an USBC console port, integrating a well known serial adapter, so no modern OS will need driver to "find" an old-but-gold RS232 interface.

The part "no WAN/LAN given ports" it's locked up to big chunks upper rank, at least 6 interface going 10.

Anyway... a lot of RAM, ARM multicore SoC, tougher NICs with on-chip VLAN management and quite good offload from SoC about "simple" things.

MultiCore PPPoE daemon.