I never understood Bonnie Ross' excuse for dropping numbered titles because they dont want to be like Final Fantasy or because it sounds "ridiculous". People using that excuse obviously never played the series.
Them dropping the numbers makes it exactly that, and the naming convention now feels more like Call of Duty, Battle Field, Assassins Creed, AND Final Fantasy making the series more susceptible to memes and such. The thing that separates these games from Halo is that they're a "compendium" of different stories within alternate timelines or universes. Halo is not. Halo is one long continuity and I am of the opinion that they need the numbers (keep subtitles if they want) for the sake of limiting confusion among the casual audience and to keep that continuity in check. But they could also be doing this to soft or hard reboot the series, scrapping everything once again for a new story which us not a pleasant idea for me.
I cant tell you the amount of people who already think Halo 5 is a spinoff from the fact that the game had a subtitle alone. And the story in that game might as well have been a spinoff from how aweful and shallow it was.
Plus I don't think really think the title "Infinite" really has anything to do with the "Infinity" I honestly think 343 and Bonnie Ross were just looking to have a catchy name hence why they want to drop numbers in favor for subtitles. They admit they wouldn't have called Halo 4 what it is in favor of having a, "super kewl subtitle!" Looking back at Halo 5, did that game truly have anything to do with Guardians? No. And I feel like it'll be the same with Infinite, it's just something that rolls off the tongue and sounds "cool" like Black Ops or World at War.
If worse comes to worse though and the title does have a significance to the story than I pray to god it has nothing to do with time travel, alternate dimensions, and such. Otherwise it WILL become like Final Fantasy, Cod, Asscreed or whatever.
Personally I say stop with using pointless buzz words as naming conventions. Psychologically people dont really like this type of naming because it breaks continuity for people and decreases interest in the next film or game within a long running series. Take Alien "Covenant" or Terminator "Genisys" for example. It's like buying different volumes of an atlas without volume numbers to help direct continuity and starting from volume 1 is "The Modern Age", "Modern Age 2", "Neolithic Age", "Modern Age 3: Advanced Battles", "Modern Age 4: Dawn of Infinite Future", "Before the Modern Age: Stone Ages", "Modern Age: WW2: Combat Evolved. Blitzkrieg Edition", "Stone Ages 2: Sticks and Stones, Breaking Bones! Bonanza! Confusing mess right, this type of naming conventions started out as parody and now making it's way into normality and its personally annoying for me, and I'm sure most everyone else dont care or think it's cool, and that's totally fine. In the end it doesn't effect me, just something I find aggrevating nowadays.