Halo Infinite will not break Halo naming system as much as people think it has. The only thing it will break is the naming convention for game with Chief as a playable character, and even then, that's debatable with Halo 5: Guardians. In fact, the use of Halo Wars 2 to advance the main story is key.
The main storyline of Halo has typically advanced with each successive main title. For example, let's look at the order of games when they take place:
A. Halo Wars
B. Halo Reach
C. Halo CE
D. Halo Fireteam Raven (During CE)
E. Halo 2
F. Halo 3: ODST (During Halo 2)
G. Halo Spartan Strike (Note this is an alternative storyline during Halo 2 built in-game virtual reality)
H. Halo 3
I. Halo Spartan Assault
J. Halo 4
K. Halo Recruit (Assumed to be during Halo 4 due to only gameplay and the fact both Chief and Cortana are on Infinity)
L. Halo 5: Guardians
M. Halo Wars 2
N. Halo Infinite
Now, if we exclude games that go back in time, let's look at which games advanced the main story:
A. Halo CE
B. Halo 2
C. Halo 3
D. Halo 4
E. Halo 5: Guardians
F. Halo Wars 2
G. Halo Infinite
With the addition of more side games and games that backtracked, the Halo Universe has largely been expanded outside of the main titular games. With the convergence of these storylines in Halo 5: Guardians, we had a change of naming structure. Then with Halo Wars 2, the main story progressed (by a little) outside of the main games. The change of name with Halo Infinite is honestly to be expected at this point. Many events in the games (not to even mention the books) are taking place simultaneously, and I think the name change reflects that. Fans have called for spin-off game surrounding the Elites, the Insurrection, Ancient Humans versus Forerunners, and earlier events in the Human-Covenant War. I expect with this change of name we will see split stories or simultaneous stories emerge in the next few games as well.