i think out of respects for both sides, They should change halo 5 simply to Halo Guardians and start their new Halo from there.
i just think it would be better direction for a Dev that seemingly doesn’t want much to do with what Halo used to be and would be a more clear and firm message on how they want it and what fans/consumers can expect.
honestly I think that’s the best at this point.
The classic Halo experience might not be around anymore so let it have its history and let this new branch of the Halo brand have its own. Don’t think there any reason for them to be intertwined it just causes friction within the community.