Well, I've heard a lot of people say that the Marvel TV series Inhumans isn't canon simply because of how poorly received it was, in fact it's not even considered and is mostly ignored by fans.
Browsing the wiki I found this news: https://www.inverse.com/entertainment/marvel-eternals-screenwriters-interview
I personally didn't know about this and I found it quite interesting. It basically talks about how Marvel Studios prevented the Eternals writers from using Hawaii because Inhumans "had already burned that bridge."
If Marvel Studios didn't care that Inhumans wasn't canon, they would have let them use Hawaii. Of course, Marvel wouldn't shoot themselves in the foot. If they haven't decanonized Secret Invasion, they would do even less with Inhumans.
This also shows that poorly received products aren't exactly worthy of decanonization, something I think Kevin Feige emphasized some time ago, they prefer to improve something retroactively rather than decanonize it.
Note: I have a guilty pleasure with this series, although it is not the best I have seen, its characters and powers are varied and creative with the small budget it had.