I suppose, "I truly believe the team have created a milestone in modern video game history" would be correct... in 2005, but this is 2021 and one of the best space-flight games ever made has just been replaced with a poor early-2000's era shooter. Not a great trade.
It's not been replaced. The "best space-flight game" is still there, and now it has more bredth to it, coming from the new first person aspect platform, which I hope to see evolve into a fully fledge RPG. Now we can get out of the pilots seat, we can do more. Currently we have limited accessable areas within stations, but the "legs" addition paves the way for more "maps" - read rooms / areas - to be added to station interiors, planetary settlements.
If you don't think it's likely that Frontier will add to the legs content over time*, look at the evolution of the game... When I joined at horizons beta, the live game was simply spaceships flying between space stations and shooting orcks each other in the void, or scanning things. By the time "Legs" alpha dropped, we could land on surfaces, interact with alien technology (thargoid and guardian structures), there is xeno biology, player owned star ports (carriers), loot and craft system (although I hate its implementaiton), ship launched fighters, surface buggies (singular)... I genuinely think they have taken elite about as far as they can from the pilots seat, and to give it "more" it needs legs.
And before you even utter the words Atmospheres or earth like worlds - I don't want to be playing "space steven hawking" I want to be able to experience the worklds first person perspective, and if you think of how much work went into microsoft flight sim, and it's only mapping one planet, with sattelite data, now to do earthlikes et al with flaura and fauna, you'd need to do it a thousand times over, and ultimately you'd still be stuck in the pilots seat. If we're getting flaura and fauna in a later update, I want to be able to scuba dive and spear gun a Lavian Lake Cuda, not shoot it with missiles from my ship/submarine, and I certainly don't want to be limited to areas of cities that are SRV accessible.
So, no, your bestest ever space game has not been replaced, its been augmented, wiht new tech that lays the framework for putting much more content in, which will take the game to beyond the next level.