oh hell yeah. we asked for it for nearly a decade. back in 2015, microsoft released a semi-open beta for a a bonafide F2P Halo game based on a suped-up halo 3 engine... in russia... and only russia. ...yeah. also P2W microtransactions. needless to say, it was mere days (as legend goes) that modders got a hold of the leaked code much to the unknowing joy of halo fans (like yours truly).
fast forward a year later (and the official game itself being shut down for further refinements), you have ELDewrito (a parody of the name of the Halo Online executible el dorado), a slightly buggy and mostly localised overhaul/mod of Halo Online remade by modders for the general public, WITHOUT the need for a proxy network.
i'm so happy. while the helmets may have an unfortunate problem of trying to be more than what they are- and hard to like, the many varied armor options and long-awaited addition of an actual RGB color slider for both armor AND visor is a very nice touch. as for the gameplay, it's halo 4 graphics alongside halo reach graphics in the halo 3 engine, albeit one slightly different from H3 and ODST from 2007/2009
when the first versions of this mod came out in 2015, microsoft tried and tried to shut them down... until they seemingly gave up. and as of 2 days before this post, I had only just heard about ELDewrito from watching a Chilled Chaos video (thanks Anthony!)
but enough of my rambling! the modders have an active community at their subreddit at www.reddit.com/r/HaloOnline/
and if you get fragged by a "Admiral Aruon" in MatchMaking... well, consider my regards sent.