Invasion is a flawed gametype.
the very nature of a large multi-stepped game-type with specific asymmetrical objectives necessitates large purpose built maps to maintain and push forward the "drama" or narrative of the game-type. the story of the game-type always needed a beginning,middle and end and map design has to reflect the three phase nature of the game-type. Which resulted in Bone-yard, Spire and Breakout being all largely useless outside of slayer. which even there because of the amount of time spent between death,spawn and return to action were almost always inexcusably long. Even with the segmenting of the map during other game-types
Now add to it that it is Spartan Vs. Elite but these two characters behaved wildly different. different sizes, speeds, health, and shields. that being as much of a tenant of the "drama" as the phases and map design.
then there is legacy. why remake someone else's attempt at innovation when you can make your own

343 is very much aligned to the Spartan VS. Spartan style of "drama" that even they were to remake the game-type the usual suspects would still have hate for it. Time is the king of development. developing large maps that have limited use for a game-type with limited appeal for a community that will hate on it for lacking elites because you as the developer prefer S v. S and have also heavily differentiated Spartans from elites to the point on even having elites as playable would be a hard sell or akin to reinventing the wheel or going with a character model in universe that can canonical match the movement versatility of halo 5 Spartans i.e knights and no one wants to play as knights. so time, design intent, purpose built maps are the downfall of the adoption of the game-type by the franchise's new parents