not everyone wanted him to be fired...

I don't think it will be terrible for the company.

Iwata was just very stubborn in producing change (for better or worse). Why is everyone treating mobile like the plague? If there's revenue to be made, it seems like a good sector to expand into. Same with licensing IP for movies, theme parks, and third party collaborations. Where are the acquisitions that they were going to make? Where is the massive third party they promised.

I liked Iwata, but I would also like the new head to be more open minded and willing to at least make the consoles more modern

It's not like Iwata kept every idea and decision to himself. Big changes won't happen for a long time considering we have Nintendo's future for the next ~7 years on paper.
And I'm pretty sure every decision was made with teams, not Iwata thinking by himself and keeping it a secret from others. Specially when you consider that the next CEO will more than likely come from Nintendo itself... Honestly, I don't get how you compare them to Konami.

Thinking about this, I believe Iwata knew his end was soon. Therefore, he set the plans for Nintendo in motion, like the Universal parks partnerships, the DeNa deals and the NX, alongside the QoL and rumored Zelda TVshow.

I'm starting to believe that health was not the only reason he was abstent at the E3, but he was making some kind of proposal for a new CEO and how to continue with the path he decided for the company.

We have to wait.

Nothing will change because the board of directors was placed there by Iwata over time as he replaced Yamauchi's old guard. The people on the board are the people with whom Iwata made the decisions he's made (as Japanese companies work in this fashion, especially conservative ones like Nintendo).

He leaves a huge hole in their spirit, leadership, and community, but the plans he's laid out for the coming decade aren't only his work. Many people were involved.

Takeda and Miyamoto will serve interim positions but Iwata's successor has likely already been chosen (and been picked for probably well over a year), and they will serve him as other served Iwata when he took power: support him from behind and give him advice.

I think it's a very good thing for nintendo but we'll see in the long run.

I hope the next guy is a little more adaptable to change but also sticks to the core values of gaming despite what the rest of the world is saying

Well Nintendo has been declining for a quite some time so this might be good thing.

I was one of the people that wanted Iwata out of and I don't think him leaving is going to be terrible for the company as long as they make the right decisions.