You have to wonder why they even admit that. The show runners of Halo said they never played the games. At this point I just think these people are just doing it to be trolls. They have to know that all that will happen by admitting you haven't at least researched the lore of the ip, is you will make fans mad. Maybe that's the goal.
They had to with HALO because they needed to make it clear that it is not the same as the existing cannon. Not knowing anything HALO, I actually enjoyed the TV show. It's B-grade sci-fi but I found it entertaining. It was better written than Kenobi.
It is interesting though, I can see some similar choices made that fall under the whole, "why is the Hollywood mindset making these choices to the detriment of the show." The same weird mindset that makes people want to brag or go out of their way about not knowing or being cannon.
You get the feeling that the mindset is that everything created before now has inherent flaws and they need to work to address those. So making it clear it is non-cannon or consistent is a virtue signal about "improving" the material.
While Halo is a better-made and written show. Incorporating a non-white male character to focus on is done better in Kenobi. As she's part of the story. Whatever made the shows do this, Halo just pushed it off into a separate storyline to cut away from the one you care about. At least Reva is a villain. Until she will not be.
What about Kylo, who committed genocide, murdered his own father, yet was redeemed to the point he even won the heart of the lead character by the end (by the demands of many fans for some odd reason) ?
Firstly, let's recognise that trilogy is a mess and there's no point in trying to make sense of the films as coherent is pointless.
Secondly, in The Force Awakens this issue was actually addressed. JJ and Kasdan recognised this problem and set up Kylo as struggling to fall to the dark side. He was actively fighting being pulled by the light. There's a line of him having too much of his father in him. Kylo was frustrated by the fact he wasn't just purely dark.
Killing his father was an effort in trying to kill the good in himself. Done to try and drive him further to the dark. Kylo had a plot to finish what Vader started. Which was dropped after the next writer didn't care to continue what was started in the first film. So whatever the entire motivation was never developed any further in the subsequent films. He at least originally was conceived to not fully have fallen to the dark side.