I honestly just miss how Bungie handled the Halo series since 343 stripped it of the gritty military atmosphere that everyone liked in Halo and Microsoft decreed it a desecrated cash cow, and I can definitely appreciate that there's serviceable ports of the first two Halo games for PC that the fans continue to maintain and create custom content for.
Though that's basically just me pining for the days of Halo Reach, when you could just stumble into players in Matchmaking and it still managed to not be reduced to a shiny chrome sci-fi fantasy made to milk microtransactions.
And yes it is entirely possible to bring back thousands of players, we could advertise to nostalgic fans that these PC ports are easy to set up for online play in [CURRENT YEAR] and point them to sites like this. Whether many of them would take that up is subjective, but some promotion of this kickass scene never hurts.