On "It's not a Concord, it's lived more than 2 weeks", the label of being a Concord feels like it's just shifted to being short hand for "Live Service that Bombed" rather than well, Concord setting the speedrun, though there's an argument whether or not that title goes to The Day Before - calling things a Concord just rolls off the tongue better.
As is, Marathon seems to be continuing it's downward player number trend, and while there might - and I stress the word might - be a bit of a spike come Season 2, I'd be willing to bet that spike fades away quickly as people realize "oh yeah this is why I stopped playing this", especially if/when we see Marathon begin to hit the "Oh shit" player count where matchmaking breaks, assuming we haven't already begun to reach that point in some servers (looking at you, Oceania)
Barring a complete overhaul of the game - which considering the financial hole this fucking game is in for Sony - my prediction is that Marathon is likely just going to go the route of "We're fulfilling our obligations then abandoning active development" rather than a sudden shut down, and that's solely out of Pride. Mostly Sony's very wounded Pride at how much of an abject fucking failure the Live Service Push has been.