This makes me think back to a newcomer to Halo I was watching play the series on YouTube a while back. He started with Reach, and then went on to CE. It was heartwarming seeing how quickly he fell in love with the series, and this was from someone that long avoided Xbox and only just recently gave it a try. He was madly in love with Halo 2, and gave 3 that same sort of support.
From the very beginning, there were people urging him not to play Halo 4 or 5, and they kept reminding him not to throughout the streams. Despite that, he insisted he'd play them anyway, and when it came time to play 4? Oh boy. Not only was he pleased to see he could Sprint (I imagine that ruffled some feathers in the stream heh.) but he said the music was godlike, it still felt like he was playing a Bungie game (Bear in mind, this was Campaign not Multiplayer), and at the end of the second H4 stream mentioned that he appreciated the fact they tried to do something different.
By the end of the game, he had placed Halo 4 as being his second favorite in the series, behind Halo 2. Because he liked Halo 4 so much, I could see some people around these parts quickly suggesting "That must have been his first Halo then lol" but that wasn't the case. It wasn't the case for me either, but I had years to get to know CE, 2, and 3. I didn't mind most of the new additions and I still to this day feel people are making way too big of a deal out of things like Sprint or jetpacks or whatever. With that being said, I'd appreciate the games with them or without them - it really doesn't make or break the games for me like it seemingly does for some others.
All that in mind, I don't think that the community as a whole is averse to change. Some might be more loud about it than others, but I think a lot of us are at least willing to give change a try and see if it works out or not. Some of these changes were overwhelmingly negative, others were more mixed. I feel that some of the things Reach, 4, and 5 did can still 'work' in the Halo games, while other things they did probably wouldn't. At the end of the day they can't please everyone, especially not after these last three games ended up bringing in a community that has a side that wants new additions and another side that wants things to remain unchanged.
I don't agree with "Change for the sake of change", but I also feel that things can't always just remain exactly the same either. Fundamentally changing an existing mechanic (like a thread suggested we do with Shields / Health Regen) as opposed to introducing a new one (Hijacking back in the day, Equipment with Halo 3/Reach/4, etc). I think it'd be okay to introduce new things to the series.